Zwift has suddenly started to freeze during the startup process and then locks up my entire PC (windows 10) forcing me to do a hard reset. It was working fine a couple of days ago.
The log files don’t show any errors, everything just freezes until I hard reboot the pc. I’ve tried resintalling everything but get the exact same result. Any ideas what could be causing the problem and how I can fix it?
same issue here. No change to anything except a zwift update
Hi guys!
after coffee I had to ride I just hyperfocused on solution of this for almost three hours, OMG
I traced that the issue is also now with other services such as steam,
its the latest windows update unfortunatelly, after uninstalling and reseting PC the zwift loads up without problems.
I would urge please the developers to try work on the solution, so I can apply the windows update which causes this.
KB5073724 (build 19045.6809 a 19044.6809)
Since yesterday, the application has not been working properly.
After selecting a route and clicking “Start Ride,” the blue screen freezes (the computer even needs to be restarted). Only few free ride routes (short ones) can be loaded.
No changes have been made to the computer or hardware. Everything was working fine on January 13.
Win10, Zwift v. 1.104.4
If the PC dies and has to be restarted, that does not sound like a Zwift problem, though it may be that Zwift is the most demanding app you run on it, which can trigger other problems. Can you share all the specs for the PC?
Hi Paul,
I5-6300hq, Nvidia GTX 960m 4GB, 8GB Ram. Zwift running from SSD drive. Not the newest laptop but was enough for Zwift to run even 1440p. In 1080p riding was smooth.
I am using this laptop for Zwift all season, and there was no problem until last update, 2 days ago.
I’ve checked drivers updates for hardware. Reinstalled Zwift, also cleaning all files manually after uninstall. Nothing helped.
The update from 2 days ago (1.105) was rolled back to the previous version, so the game is the same as it was 10 days ago.
When you re-installed, did you follow this process to clean up all of its data files?
Your hardware should be adequate. If you’re running one of the latest Nvidia drivers, I would remove that and use the one that comes with Windows 10 since that’s generally stable and there are no benefits to running newer versions.
Other general recommendations are to remove OneDrive and any anti-virus software other than Microsoft Defender.
Thank you Paul for suggestions
Yes, I did cleaning as described.
Checked other suggestions and uninstalled all Nvidia drivers and soft. Again clean Zwift install. Removed OneDrive app.
I don’t use any custom AntiV but I don’t think this (or OneDrive) could be the issue. It would block Zwift permanently. I my case I can load some small routes without issue (The classic) but when I choose something bigger 10-15 km or more it will freeze. The same if I try to use “Just watch” from Pairing screen. After few seconds everything freez, even mouse pointer and can’t open Task Manager. Only hard restart.
After two days of trying I give up 
unfortunately need to try some other platform.
There is another bug that has come up recently that you should check for. Look at the size of your log files in Documents\Zwift\Logs
I bring that up because I would expect it to make OneDrive go nuts.
I noticed that the problem affects certain worlds. At first, I thought it was related to small routes and looked for the problem in my computer’s performance, but it seems that the problem lies in the application. Checked again some routes and I can go any route in London and Richmond without any problems, but Watopia or Scotland (Event) crashes my computer.
I will wait for worlds change and/or update
The CPU demands vary depending on which world you are in, so it’s not unusual when you are at the limits of the CPU that things work OK in some worlds and not others. I recommend uploading a log file to trainerdx.com and sharing the results here if you want feedback about how it’s performing. I would expect that rides in Makuri would also cause problems so you could test that as well.
Thank you Paul, but I don’t think the PC performance is the problem here.
Every log after issue is empty only with different duration saved.
Richmond successful world loading as an example:
Unfortunately don’t have older logs to compare as I did deep cleaning while reinstalling Zwift.
I’ve even reinstalled my Win 
…so let’s leave it. I will check after next updates.
tbf zwift often goes not responding for me when loading up the world initially, but its been doing this for a long time
That CPU graph shows total CPU utilisation across all four of your cores. What you need to look at is CPU utilisation across each core, because Zwift is single-threaded and will only use one core.
Your system could be maxing out the core that Zwift is on yet only show 25% total CPU utilisation if the other three cores are idle.
same issue here, windows 11. PC works fine until i start zwift. Was fine yesterday,
Hi @Lenka_Komarkova and welcome to Zwiftt forums.
Shuji at Zwift HQ here. Thanks for providing this valuable insight.
For other Windows users - please check to see if an OS update might have been installed since your previous Zwift activity, and roll back to the previous version of Windows. See Microsoft’s support article for instructions.
Please let us know if this solves the issue (or no).
Hi,
I’ve got the same issue. Latest windows version was installed yesterday, since I cannot launch Zwift (see original post).
I would like to back one version in windows, but there is no “go back” option in recovery for me.
Is it possible to test the latest version at zwift hq ?
Is this because you don’t have admin permissions on your machine? Is this a work-issued laptop?
Thanks all, rolling back that update has fixed the issue for me.
