Update for Tuesday, July 27th: Zwift released a patch today with the following notes:
- Fixed an issue which would cause FIT files to not be saved correctly in some cases.
- Fixed an issue which would cause a crash when saving an activity if you started your Zwift session by fan viewing another Zwifter.
- Fixed an issue with workouts that would cause power targets to appear higher than they should during rest intervals.
- Fixed an issue which would cause a paired smart trainer or power meter to prevent other devices from being successfully paired.
Additionally, Shuji posted the following on the thread about avatars weaving: “Pack Dynamics were rolled back to the 1.14 version late yesterday on the server end.”
Based on these notes, we’re hoping that at least four of the five issues discussed below have been resolved with this patch. That’s great news!
Not long after Zwift released their latest update, Zwifters began reporting significant bugs in the release.
Today, a week after the release, specifics about what each bug does, who it affects, and any possible workarounds are becoming quite clear. But that info is buried in forum topics on Zwift’s site, some with over 300 replies! So we’ve put together this summary of the bugs, along with any information we could gather on workarounds and planned fixes from Zwift.
.fit File Data Problems
Zwift’s release notes said they “Fixed an issue that would cause an activity map to show an incorrect path (very long line) when Zwifters moved between events, meetups and free rides in the same game session.” But in doing so, they have introduced a bug for Apple TV, iOS, and Android users which breaks the .fit files for certain activities.
It appears what is happening is, if you do one activity, then jump into an event of any sort, the fit file saved for that event is a duplicate of your previous activity. So, for example, if you warmed up for a race, then joined the race, the resulting race activity’s fit file data would simply contain your warmup. But the .fit file is also corrupted in some way on top of this.
This is a serious bug, as the .fit files are lost forever when the bug bites. Your activity isn’t uploaded to Strava, TrainingPeaks, etc, and it’s not retrievable from Zwift’s servers or your local machine.
Platforms affected: AppleTV, iOS, Android
Workaround: there is a fairly simple workaround which seems to be get around the bug. Simply force-close the Zwift app before starting each event. Then re-open the app and join your event. This makes sure your previous session is terminated fully.
Status: Shuji posted in the forums 5 days ago that “Everyone – this bug has the highest priority. I’ll update this thread as we make progress toward the patch to fix it.” ZHQ is telling us this will be fixed in a patch which will hopefully be released in the next day or two.
Read the Zwift forum topic for this bug >
Riders Weaving On the Road
Zwift updated pack dynamics in the latest update in an attempt to keep us in a more consistent lateral position in the pack, and to avoid losing speed when colliding with others. And it seems to work fine… except on maps where we ride on the left side of the road! That includes Makuri Islands, London, and Yorkshire.
Riders in these worlds are complaining that when they overtake another rider, they swerve way too far to the right to ride around the rider. Multiply this by every rider in a pack and races get messy quickly! Additionally, riders are being placed on the center line of the road, meaning they’re playing “chicken” with oncoming traffic.
Group ride participants are complaining that this is making sweeping impossible, and racers are saying it dramatically changes the dynamics of the race pack. Some riders have quit events because they can’t watch the screen without getting motion sickness.
Here’s a video showing the behavior in London:
Platforms affected: all
Workaround: none, except for avoiding riding in the affected worlds
Status: Zwift is still investigating this bug, so a fix is unlikely to appear in the upcoming patch.
Read the Zwift forum topic for this bug >
Can’t Pair a Power Meter + Controllable Smart Trainer
Many Zwifters use a dedicated power meter such as the Assioma pedals as their power source, while also connecting to a controllable smart trainer for an immersive experience. After the latest update, Zwifters are finding they cannot pair a power meter, then a controllable smart trainer when using Bluetooth for all connections.
Platforms affected: all using Bluetooth connections
Workaround: there are multiple workarounds which should get you up and riding:
- Use this specific sequence to connect your hardware: first, connect your smart trainer as the power, cadence, and controllable device. Then disconnect it as the power source. Then click to connect a new power source – your power meter should show up.
- Some Zwifters have changed to connecting their power meter and smart trainer using the Companion app instead of direct-connecting their Zwift device.
- Another approach available to Zwifters with ANT+ capabilities on their Zwift device is to connect using ANT+ for either or both the power and controllable connections.
- Lastly, you can simply connect your smart trainer as your power source.
Status: Zwift is still investigating this bug, so a fix is unlikely to appear in the upcoming pat ZHQ is telling us this will be fixed in a patch which will hopefully be released in the next day or two.
Read the Zwift forum topic for this bug >
MacOS Crashes
Mac users are reporting app crashes before they can even get into the game. The message looks something like this:

This appears to be a problem on multiple versions of MacOS.
Platforms affected: MacOS
Workaround: a completely fresh Zwift install seems to fix the problem for some. See the forum topic below for instructions from some Zwifters.
Status: Zwift is still investigating this bug, so a fix is unlikely to appear in the upcoming patch.
Read the Zwift forum topic for this bug >
ERG Intervals Incorrectly Displayed
The latest update included this bug fix note: “Fixed an issue during a workout where multiple watts values were displayed incorrectly.”
Unfortunately, Zwift’s “fix” introduced a new and obvious bug, in which on/off intervals are showed as using the “on” power for both intervals. That makes for a painful-looking workout! Is Zwift pranking us? Here’s one example (the 2x and 15x blocks should have a hard interval followed by an easy one.)

Fortunately, this is just a display issue – you can still do the workout and it will have you hold the correct wattage intervals. But it sure looks scary in that left-hand bar.
Platforms affected: all
Workaround: the Companion app still shows the intervals correctly, so run that with your ERG sessions to see what’s coming up.
Status: Shuji said, “Yes, we are working on it!” in the forum topic. This looks to be a quick fix, so hopefully it’ll be included in the next patch.
Read the Zwift forum topic for this bug >
Wrapping It Up
Zwifters have long joked that when Zwift releases an update, they create more bugs than they fix. And while this hasn’t generally been true, Zwift’s latest update clearly included some big bugs that severely impacted Zwifters’ experience.
We can forgive silly small bugs like missing pedals or piggyback riding in spawn points, but when you’re unable to complete or save your planned activity it’s a super-frustrating experience. These issues should have Zwift’s full attention because let’s face it: big bugs are bad for business.
Hopefully, ZHQ learns some lessons here and releases more stable updates in the future. But first… we hope they can quick-fix the bugs above!
Tips, Questions, or Comments?
Got other workarounds for the bugs above? Share below!
(Questions or comments for issues you’ve encountered with the latest update can also be posted below, but will probably do more good posted on their respective Zwift forum topics.)
As always, your very useful Eric.
Thanks for keeping us all in touch with zwift. 😁
With the amount of money Zwift in raking in, you’d think they’d be able and willing to hire on some competent people to get things up and running as they should be, without all it’s myriad bugs and other issues. Every time they roll out an update to fix this or that, they wind up breaking something else.
This just requires suitable regression testing, Zwift are acting like a start-up and need to invest in testing.
Thanks Eric. I’m starting to get pretty bored of these Zwift bugs with every update. The joke “I wonder what they broke this time” isn’t really a joke now.
MACOS CRASHES Is happening for Windows as well since update … as noted above same workaround/fix to uninstall the Zwift app and reinstall it…
Yep, I had that on Windows 7. Note you have to fully uninstall, which involves deleting a bunch of folders. Just running the normal install didn’t cut it for me, I had to follow the instructions here: https://support.zwift.com/en_us/re-installing-zwift-BymCF82TH
I just thought people with Sterzo units were trolling everyone in London this morning. Guess it’s a bug, but not one that will keep me from riding that map.
This is why I call it a Bugdate. There is always a couple but this month they’ve out done themselves. I love Zwifting but these kind of things are becoming an embarrassment. Sort of a guilt by association…
Yeah, the power source bug was introduced a good few updates ago because I swear I started seeing it back in May.
I have a Wattbike Atom which I prefer to connect via ANT+ as I get a more reliable signal for that for some reason, but in order to see the gear changes on screen, I need to connect the Controllable option via Bluetooth. Used to be able to mix and match like this no problem, but now the pairing screen won’t let me, unless I jump through all sorts of hoops first of connecting and disconnecting various options.
I guess we’ll seeing some fresh job postings for software dev’s and software QA ?
Thank you. When you say force close the app, do you mean that, instead of entering an event when you get the “Join Event” notification, you disregard it, close the Zwift app and log in again?
Yes. If I was racing, for example, I would open the Zwift app and ride my warmup. Then when it was time to head to the pens, I would save my warmup ride, then close the app entirely (swipe it up on an iPhone, for example).
Then open the app fresh, sign in, and join the event without doing any riding beforehand.
Thank you 😊
Not sure this is always a successful workaround – I did this and it only saved me a 4 second file from starting and then joining event. No event file.
Thank you for this update. Just jumped back on zwift (heavy wildfire smoke), joined a race then rode with pace partner, and it all ended up on Strava as zeros. Nice re entry to reactivate subscription and have your first ride basically deleted…but good to know it’s a HUGE bug.
thanks! Sometimes it’s just helpful to know that you aren’t the only one having a problem. (I have .fit file issue). Thankfully, I have very few issues over the years so I forget to check the forums – great reminder 🙂
thanks!
The ERG Intervals issue. You can still use the Companion App as that still displays the workout correctly. I nearly cried this morning when I saw the workout I had been set, luckily the App soothed my fears!
Yeah, had been scared for some 20min during a quick session of the “Leg Openers” yesterday until I got to the first “off” interval… 🙂
Good tip! I’ll add that above.
Great summary Eric, thank you!
Disappointing that Zwift team doesn’t roll back the update, analyze all available data at hands, and release new changes in an controlled environment step-by-step e.g. specific races / events.
Zwift have some major issues with QA and testing these updates before release and while they are still okay now, the playing field is starting to get heated so they better watch their backs or there could be a mass exodus from the platform. Hopefully they start to improve and maybe focus on the core of the platform (and making it stable) before releasing “new” content. I did experience the steering bug in London on Sunday during the MS event and it was terrible (Chris C. the ride leader said it best when he said maybe Zwift should just throw… Read more »
I forgot to mention that their Events team is having some “small” problems as well as events are either not showing up (posted) such as the final Norseman workout or they aren’t put on the calendar until the last minute (the Norseman main events are next week and still haven’t been posted which is beyond ridiculous at this point in time). I have to assume (hopefully I am wrong on this) that there are major issues going on behind the scenes that we as riders aren’t seeing and may never know about. Hopefully they can get things sorted out and… Read more »
Thanks for this, Eric. I had to quit an event the other day as I’d become motion-sick and it had simply become unbearable. Lateral stability improved???…my A$$!
I think some of the problems zwift have is that they seem to need to release an update every month and so in order to hit their date target they don’t have time to properly test stuff. I’d rather fewer updates but ones with fewer bugs.
Dont know about anyone else, but since the update, I cant refresh “MyZwiftFeed”, it goes to a blank page. I have to close the tab, and re-open.
I feel like the Wahoo Kickr incorrect gradient handling bug has become more frequent for me on my V5. I know you can revert the Kickr firmware back to resolve this as recommended by Zwift but Wahoo has recommended against that. I love Zwift but the fact that probably the most popular trainer can’t consistently perform the core functionality of the game more than 50% of the time is crazy to me.
I had this problem. I deleted Zwift and unpaired the turbo from the app, basically started again. Once all loaded and paired I did the Wahoo spin down then the Zwift spin down, I’ve not had any problems since.
Thanks for having highlighted this issue over here on Zwift Insider, Eric. A real mess for a lot of people, this month. About 30 minutes ago, Wes Salmon of ZHQ went on the Forums and announced: Update 1.15.1 – July 27th. We’ve released a small patch for this version to address a few bugs
@eric:
Update 15.1 has just been released (at least for iOS).
And here I am still waiting on the ability to actually be able to link my Garmin connect account. They really need to hurry up, it’s been so long now.
Based on what we know about the Mac bug, it seems to me that QA at Zwift is being carried out by Drs Dunning and Kruger.
It’s a joke, they have no automated testing to catch obvious issues. The mac bug is just a hard coded dev path, that only works on one Zwift staff members computer but they still haven’t figured it out. Lol
The MACOS crash at startup is also happening on my WIN10 PC with same message. reinstalling doesn’t fix.
A trainwreck. Poor software implementation quality/assurance roll-out process. They definitely need to up their game on this front. They are a mature enough company now they should have clear beta protocols, etc.
I could not for the life of me get my Apple Watch to pair with zwift yesterday nor my wahoo pedal(rpm) counter.
it would only accept the connection from the wahoo kickr so I think that bug remains unfixed.
The swerving issue with the avatar has made it were I don’t even want to use Zwift anymore. If you come close to someone your avatar swings all over the place. It is an incredibly frustrating riding experience.
I wish they just they rolled back the code from 2 years ago when the drafting dynamics actually worked. You didn’t get stuck on riders and you didn’t swerve all over the place.
Hi, since the bugs, my iPhone Companion, does not connect / display map. I use AppleTV. Any hack to fix this, please? (I have done the obvious stuff, like uninstalling / installing the Companion App, Logging out and in again, restarting everything.)