What you did
Open the browser
Open a website
Navigate to the forum
Check the forums which subforum might be the correct one
Ignore all that is there and just start a new thread
Think about what to type (and the text, as Sharlikran already wrote, is kind of a very "it worked before and now it doesn't" without any details...)
Type it
Wait for angry answers because we repeat ourselves here for thousands of users who are simply to lazy to read and help themselves EVEN THOUGH all info was provided already AND the forum search would find it properly easy too.
What you should have done instead
Open the browser
Open a website
Navigate to the forum
Check the forums which subforum might be the correct one
Read the top sticky threads at this forum (Addon help)
and
Use the forum search to find similar issues
Find out, by the sticky thread "[HOWTO]Find the addon install directory"
https://www.esoui.com/forums/showthread.php?t=8858 and similar that your issue is either related to Microsoft OneDrive or your live/AddOns folder moved to AppData maybe (-> find out by the help of the Screenshot trick).
If that does not fix it, think about what to type, tell us what you did read and tried already, or where you need help to understand, instead of writing us something like "Yesterday all was fine and today not".
Maybe add screenshots, list of enabled addons, LibDebugLogger log files like described at "How to report errors" sticky.
I hope it's understandable that we somehow get annoyed by that kind of posts here, each day, again and again. We are not here to invest our time (on top of creating and maintaining the addons in that time already) to fix/support your laziness guys, thanks for doing research on your own AND providing info what was done, in detail, screenshots, LibDebugLogger log file, error code, etc. so we are at least able to properly help.