Same problem with After Effect 17.0.5

Specs:
ThinkPad T495
Ryzen 3700U
Vega 10 iGPU
24 GB DDR4

OS:
Windows 10
Version 1909
OS build 18363.778

I lost at least 3 hours of my time restarting AE and finding a way to fix this, only to figure out that rolling back to AE16 fixed everything in my case (which I'd recommend you to do).

⚠Tip to everyone having the same issue⚠

If you right click on the icon on the Windows taskbar and click "Close window", AE will still save your file before closing. This won't work if you were working on an untitled/unsaved project since AE won't be able to display the "Save" window and thus you'll freeze the whole thing for good. So, albeit the fact that you still need to restart AE every time it happens, you get to keep your progress

I'm having the same issue since last update--Can't stop preview.
AE 17.0.6 Build 35

iMac (Retina 4K, 21.5-inch, 2017)
3.4 GHz Quad-Core Intel Core i5
32 GB 2400 MHz DDR4
Radeon Pro 560 4 GB

so what is the solution? I've been trying multiple things listed here for two days now. I just reinstalled to 17.0.6 and still having issue. I was NOT working off cloud and had not had an Adobe upgrade for the past month or so. I worked on a similar project a month ago with zero issues. I opened that project up and was having this same issue.

Ergh so infuriating! I have wasted so much time today install older versions - I don't want to speak too soon but I've just installed 17.0.4 and it's working fine. Fingers crossed it stays working fro the rest of the day!

I'm also still experiencing this, I tried going back a few versions and it still persists. One thing I have been doing that works some of the time is to right click your AE app icon in your menu bar and select close. This will sometimes break the loop with a save prompt. Doesn't work all the time but I'd say about 70% of the time it works.

When is Adobe going to fix this...............

Yes, Luke Howell. I am still experiencing the problem.

I'm still experiencing this bug in the latest update 17.0.6
I have tried installing older versions, a complete reinstall, older GPU drivers, importing a file into a new comp. Nothing is working.

Are others still having the same problem?

After Effects gets worse with every release.
My RAM Preview is not working either.

Windows 10 Pro. Xeon Workstation. Quadro. 32GB RAM. Samsung SSD, Wacom tablet, comfy chair, glass of beer, etc, etc, etc. It doesn't work.

This hast to be the most annoying bug ever.

Win10
Xeon E5
64 GB RAM
Nvidia 1080ti

I tired installing an older version. Just a couple dots back since everything other program is working, and that is seeming to work tonight. I can at least work and move forward. So until they fix it I just went back a couple versions and I can actually get stuff done.

Same.
Windows 10 Pro
AMD 3900X
64 GB RAM
2x 2080

Also, playback speed is horrendous too. Can't play a stready 60 fps 1080 composition in a 4K monitor if any interface is showing.

I have the latest version of AE 2020 (17.0.6) and I still have problems with playback which none were present in 2019. I push spacebar (or from the preview menu itself) to preview, it starts but then it wont´t stop, I have to force quit the program, this only happens with the Windows version, in MacOS it works fine, I just had to move my entire project to MacOS because otherwise I could not work. PLEASE fix this, after many updates of 2020 this bug/issue persists!
That's what happens when it plays the preview, sometimes it just won´t play no matter what, I have to close ÁE, open it and preview again and do that process all over again everytime it won´t even start the preview.

I've just stumbled across this bug in 17.0.6 (Build 35). Its only started doing this. Soo Annoying!

i have had problems with Audio device changes and then no ram preview working as well.

Windows 10 Pro
AMD Threadripper 2950X
64GB Ram
Nvidia 2080ti

What kind of file do you need to see more system info?

Not really a fix, but I was having the same issue. After creating a new project file and reimporting everything from the old project file everything previewed normally again.

PLEASE STILL FIX THIS FOR REAL ADOBE. Hours lost trouble shooting this.

I have been able to reproduce this error.
1. Toggle ON the "show overlays and layer controls" option under Spacebar Preview
2. Ram preview using space bar.
3. When the work area is fully cached, hit spacebar to stop
4. Press spacebar again to play back the ram preview, and often the playback will get stuck (I can't stop playback and have to force shutdown AE).

I'm not sure if these factors are important, but I had several Null objects with position data applied to them. I am working at 32bpc in full res. Playback is also set to loop, not play once.
I am on Windows 10, AE 17.0.4, NVIDIA driver version 430.86 with a NVIDIA Quadro RTX 6000.

Happening here on a Windows 10 with studio AND game ready drivers, so not resolved. Also, playback speed has definitely taken a hit and many of my students can't ever hit full speed so much so that audio doesn't even play (when using don't play audio if not full speed).

Known issue. This should be fixed in an upcoming version.

Same problem with After Effect 17.0.5 on Windows 10, Ryzen 3700U with Vega 10 GPU.

AE16 is working like a charm tho.

I also just discovered that it is in fact the Nvidia Studio Driver that's the cause. I downgraded to 441.66 and now everything works.
In preferences -> previews the gpu is also being recognized again