Hello,
Think you might have a old version of Elvui running or it broke somehow? There seems to be a lot of backdrop issues. Patch 9.0 changed how background color in windows or frames is done in the game. So if your version is old you can get many lua errors due to that but i did not read through it all so you might have some other addon messing with you. Are you using any other addon for name plates then you could try disable nameplates in elvui and see if it fixes it.
OR YOU COULD TRY REINSTALL ELVUI BUT I STRONGLY SUGGEST YOU ASK IN A OTHER FORUM SO THE AUTHORS OF THE ADDONS CAN HAVE A LOOK AND HELP YOU BEFORE YOU DO ANYTHING IF YOU ARE UNSURE IN ANY WAY.
The latest version of Elvui is 12.80 i think and you could try reinstall it and see if that fixes your issues.
Do a back up of your WoW addons by saving a copy of your Interface and WTF folder to a other folder or drive.
If you are having troubble finding your location of your wow folder you can try this way.
- Open your Battle.net desktop application
- Select “Show in Explorer” from the cogwheel options list next to your play button
- Click on the “World of Warcraft” folder
- Select the version of the game you play (Classic or Retail)
- Copy the “Interface” and “WTF” folders
- Paste them onto a hard drive, cloud drive, or another location
Then Delete both ElvUI and ElvUI_OptionsUI in your retail\Interface\AddOns folder, then grab a fresh copy of 12.80 from the website or client.
Do not replace or overwrite the files, it is important to delete the old folders first.
But as the others said here that if you are unsure the best is to go to the addons page and ask for help there.
Good luck and have a nice day.