UPDATE: Zwift released a patch on Friday afternoon, version 1.33.1, which seems to fix this issue.
Yesterday’s Zwift update appears to have affected ERG mode for some Zwifters, resulting in Zwift not controlling your trainer resistance as it should in ERG.
There’s a long forum thread already developing around this issue, and Zwift is working on fixing it. (I’m sure it’s a top priority, since ERG workouts are a very popular activity on the platform.)
Based on the reports I’m seeing, the problem is largely restricted to Windows users. It’s occurring both on ANT and Bluetooth connections, on a wide variety of trainers. So the issue doesn’t seem to be trainer-specific, or even connection-specific.
I tested it on my end with Windows 11 via ANT and Bluetooth with a KICKR v6. Interestingly, ERG worked properly for me with Bluetooth, but did not work with ANT.
Quick Companion Workaround
While some users are saying that restarting Zwift or swapping between ANT and Bluetooth connections fixed the problem, the only reliable workaround at this time seems to be switching to using Bluetooth through the Companion app as your trainer connection, instead of ANT or Bluetooth on your Windows machine. Here’s how to get that done…
Prerequisites
To use Zwift Companion as your trainer connection, you’ll need to:
- Have the Companion app installed and running on your phone/tablet
- Have your phone/tablet on the same local network as the PC you use for Zwifting
- Have Bluetooth connections turned on on your phone/tablet, so Companion can “see” your trainer
Simple Steps
Once you’ve got Companion running as per above, follow these simple steps:
1: Start up Zwift on your PC
2: On the Pairing screen, click the gear at the top-right and select “Use Zwift Companion”

3: In the “Controllable” box, choose the item which shows your trainer name next to a mobile phone

You should be good to go!
Related Issues
Some riders are reporting that gradient simulation in Zwift isn’t working properly either since the update – this is probably related to the same bug that is affecting ERG mode.
Also, I noticed that the Companion app didn’t properly show my workout details as rode. Instead, it showed this super-goofy screen:

This bug has been reported to Zwift and seen by multiple users as well.
Questions or Comments?
There are a few other bugs popping up with yesterday’s update, which I’ll add to the main release post. But if you have comments or questions about this specific ERG bug, feel free to post below or on the forum thread.
Is this related to the known existing issue of the hubs not registering any power or speed when attempting a spindown calibration?
In addition to not registering power or speed from hub in game mode?
I don’t think so. Haven’t heard of this Hub issue…
Not much help for a workaround when companion on my phone keeps disconnecting.
Turn off the setting that allows your phone to jump to call when there’s a poor Wi-Fi connection. May be called “Wi-Fi assist”
Note that this issue is not limited to Windows. I run Zwift on MacOS and ERG failed after the update today
Yep, MacBook Pro with iPhone running companion for me. Plenty of ERG issues for me as well.
Yep, same on my Macbook Pro. Took two restarts for it to start working better but still had some issues, particularly noticeable on the downhills where resistance didn’t change.
I can’t even ride. I can’t get power to register into game in any way. Work around didn’t work either. I tried but performing the update so I could do my workout, but that wasn’t an option. Now it is fully broken and I can’t even ride. Super infuriating I’ve been a subscriber since beta. Terrible.
My smart trainer wasn’t so smart after the updates (PC). i Then discovered that the update had deleted my Ant+ driver.
Cancelled my Zwift subscription yesterday. This was the final straw that broke the camel’s back.
So many better options out there: I have always used 2 x indoor platforms (Zwift and Fulgaz).
Sure, I’ll miss the racing aspect of Zwift. But I won’t miss the buggy, inconsistent, blood-boiling glitches Zwift brings.
Zwift are basically abusing our loyalty to the platform and their dev/testing team becoming a laughingstock. Kudos to you for saying enough is enough.
Thx zwift, you fucked up my training with the update ERG not working
ERG and gradient simulation were both broken for me too – but at least gradient simulation could just be fixed by changing trainer difficulty (under “Settings”).
It seems that the update overwrote the value with “0”, and changing it to any value resolves the issue.
Gradient simulation is borked for me on Windows (with Ant+) and switching to bluetooth connection through Companion did NOT work. Does no one do QA at Zwift? Not like this is some obscure corner use case…
Following up on myself:
Adding a bluetooth dongle to my PC and unplugging the Ant+ dongle worked! I now have gradient simulation (aka sim mode). I did not test erg.
Note that changing Trainer Difficulty, restarting Zwift and/or rebooting PC, as well as combinations thereof, had done nothing for me. Nor did using bluetooth through Companion work, as noted above. Only adding a bluetooth dongle directly to the PC (which does not have native bluetooth) did the trick.
Workaround didn’t work for me. I’m running the latest Zwift update on a Windows 10 pc, and I made sure to also update my Companion app. on Android today. Tried the workaround but got “No Signal” despite making sure that bluetooth was on on my phone and the trainer’s bluetooth signal was flashing as working. I gave up trying after disconnecting my Ant dongle to make sure that wasn’t interfering. Instead I just did a free ride. But I sure hope Zwift comes out with a fix right away. I depend on my workouts in ERG.
I had this issue on my macbook so not just windows
Zwift is unusable in any sensor combination now.
Fwiw, I had no issues with ERG this evening. (Drops were messed up though.) I’m on Windows 10, Bluetooth.
Same here, but using Mac Mini with bluetooth.
I do not want to sound like many people who bash Zwift in comments claiming they will go somewhere else but… I will use my work around: I will be to trying another platform this weekend. After a crash filled January during events, not being able to race tonight was too much for me
It happened to me a couple of days ago. I was concerned it was my new laptop not supporting ANT+. Workaround for me was to turn off Bluetooth on every device that connected to my trainer and have Bluetooth forget it in one case. I then used the Wahoo app to connect to it and do a spindown. After that, i went to my laptop and started zwift. I saw the trainer was finally visible in the pairing screen, so i selected it. I couldn’t get calibration done with Zwift, however. I decided to ride around and see what happens.… Read more »
My experience with this issue (Saris H3 and W10) is that zwift isn’t fully syncing fully on the pairing screen. Zwift will read power from the trainer and show the trainer is connected but trainer doesn’t link for control.
Work around: go to trainer spindown/calibration on the pairing screen. Start the spin down but instead of pedaling I unplug and plug back in the trainer. Trainer fully sinks and gradient/erg/slope work!
Worked for me! Thx!
Hello,
Will Zwift send an update that this is fixed. Workaround don’t work for me 🙁
Thanks,
Marcin
Fix tomorrow (28th) apparently.
Eh?
A patch is being released soon.
Today I used the Wahoo App on my phone to adjust the gradient of my Kickr. Bit distracting but managed to ride Tour de Zwift today.
I havent teste erg mod on workouts, but the gradiente isnt working for the first half and hour, then start working from nothing…
I’m betting they don’t do QA testing by actually having a real live person ride a physical trainer. Input is all simulated..
Unless you are a software developer, I would hesitate to bash on their testing. From experience, it’s very hard to test EVERY aspect of an application when doing an update. Your testing environment is never the same as a production environment. It’s easy to miss something. Cut the Zwift Devs some slack. If you can’t work out for a day or two, it’s not the end of the world. They will get it fixed. Zwift is still the best thing that has come to indoor cycling. I’m sure it’s brought all of the complainers MONTHS maybe YEARS of great workouts.… Read more »
I’m a software developer and I used to do QA. This is frankly embarrassing for Zwift. This isn’t an edge case that only affects a minor feature for users on some obscure platform/device. A key feature (ERG workouts) is broken on probably their most widely used platform (Windows). This bug never should’ve made it into production.
Of course it’s embarrassing, but as a dev, I take it you’ve never introduced a bug to production that you’ve had to scramble to correct? Mistakes happen. Not the end of the world.
Nothing this major, no. It would’ve been caught in QA if I didn’t catch it myself in my sandbox before I even sent out a pull request. Sure it’s not the end of the world, but Zwift *is* ERG mode workouts for many paying users. The description for the “Jon’s Mix” workout says, “Jon’s Mix was developed by Zwift cofounder Jon Mayfield, and it’s widely used by the Zwift development team to test features.” If this were the case, it would’ve been immediately apparent that ERG mode was broken.
I don’t work as a developer but have a relevant degree and run a company that does software development. There are always things that make it through QA because they are niche and you can’t retest everything after fixing minor, seemingly unrelated bugs. Most things will get caught in automated testing though. Everyone knows that and most users are OK with it. That’s not what happened here though. ERG mode during workouts is like Microsoft updating Office without testing if Pivot tables still work in Windows 10. Mistakes happen everywhere. Sometimes they show that something is fundamentally wrong with the… Read more »
They never seem to have any bugs while trying to process my payment.
The last thing we need is the user base making excuses for Zwift. That’s how they can abuse loyalty and not address what appear to be fundamental shortcomings in their development process.
The release notes say “Fixed a bug that sometimes caused Trainer Difficulty to revert to the max setting”. So even if they couldn’t do a full regression test of the entire application, they should have tested this area of functionality. This is software 101.
I can only partly agree with you, Anthony. There might be some pressure to release Scotland. We all would have loved this update if it had just been that, because we all love new maps. Releasing a fatal (!) bug turns this actual good news into a disaster. If you have to manage a situation like this on a Friday right with your weekend ahead, I could imagine also a blow for the stuff as it affects nearly all departments in the company. Don’t wanna know how angry I was if something similar happened to me on work. I have… Read more »
After this release Zwift needs to move to a public beta program model. Their current method of testing and releasing software isn’t scaleable with the number of users and device+OS combinations on the platform.
Zwift is already running a public beta programme. They release beta software to all their paying subscribers who find the bugs and report back.
Since the latest update, my trainer (Wahoo) no longer changes resistance. Also my Kickr Climb no longer works. Hope Zwift can fix these issues soon
While racing yesterday I felt like the climbs were non existent while going downhill felt like I was on a 8% grade. Also, the resistance would erratically increase for no reason so i had to put extra power in just so I wasnt pushing 40rpm. Very frustrating.
Same for me. Seemed better today 28th Jan.
Trying this, but when I go to the step of choosing the “phone” trainer…it isn’t there to choose. Only the ANT+ shows.
App connects fine, shows map/game. The BT trainer option isn’t there.
What am I missing?
Ok. a fast follow up if anyone else is having this issue.
The above was missing a step for me.
I had to select the phone trainer in the POWER SOURCE first, THEN it showed up in the CONTROLLABLE. Without doing that, I was only seeing the ANT+ trainer.
After I did that, I tried a erg workout, and it appears to be working. I’ll know for sure tomorrow, when I have time to actually do a workout.
Thanks for workaround but I only brought a Ant + dongle and that’s all I needed. So basically Zwift are telling their new update is broken their own software and the only workaround requires me to buy more kit for which I shouldn’t need.
You don’t have a phone to run Companion on? That’s all you need. No Bluetooth dongle or anything like that…
1.33.1 came out a couple of hours ago. Seems to fix it.
Yay — I just did a quick test, and ERG seems to be working again with version 1.33.1.
Thank you for the work around Eric
I think i have the resistance bug fixed but i have noticed a distance bug. Example: Ride “Roud to mountains” and yo will notice flexible distance from start, to start of climb.
I have it on two phones and tablet…wtf ?! What with that case, how to make it work? My last month with that app, I will test mywhoosh and bkool.
Since the update my issues with connecting trainer to zwift have got gradually worse. First off it stopped adding resistance with ANT+ connection then got dropouts on bluetooth. Now the ANT+ connection won’t work, on the pairing screen it’s greyed out with warning triangle next to it. Seems hit and miss before the option becomes available to pair with bluetooth over the companion app to use the workaround from here. Re-install of zwift made no improvement, found error against the USB/ANT+ device in device manager and played around with drivers which seems to have got it working again but nothing… Read more »
I’m still having this problem. When is the next update expected to be launched? Are you still facing this problem as well?
I’m doing the FTP builder. Is it possible to do this with erg mode off? I tried several times to turn it off and it kept coming back on.