After installing an add on, I was no longer able to open the anki app on my windows computer. When I open the app, a flashing windows appears that reads “Anki encountered a problem. Please follow the trouble shooting steps. Add on possibly involved: 538879081.” The window flashes on and off of the screen so fast however, that I am unable to interact with the main anki screen long enough to view to follow the trouble shooting steps. I also tried to press the shift key to start up anki, but the window still appears and the problem persists. I have also tried to completely delete the anki app and its files from my desktop but when i redownload it, the window still flashes rapidly, preventing me from accessing any menu from the main screen. I tried to attach a video of the screen but was unable to. Let me know if any other info is needed.
Did you hold down Shift for long enough to see the confirmation message?
If that doesn’t work (and it pretty much always does) – your other option is to go to your Anki2 data directory (Managing Files - Anki Manual), to the addons21 folder, find the 538879081 folder and move it somewhere else or delete it. That will “uninstall” the add-on, and let you start.
The lesson you should take from this? Don’t install add-ons that haven’t been updated for 4 years and aren’t compatible with your version of Anki!
You can see the last updated date at the top of the add-on’s page, and the version support directly above the ID you had to copy to install it.
Or maybe just read the recent reviews?
(Oops! I don’t know much Portuguese, but I recognize a couple of those words! 
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