I had this problem aswell, so I checked the Logs --> FrameXML, and saw this:
Frame PetBattlePrimaryUnitTooltip: Unknown script element OnClick
Loading add-on ElvUI
** Loading table of contents Interface\AddOns\ElvUI\ElvUI.toc
Couldn't open Interface\AddOns\ElvUI\
Couldn't open Interface\AddOns\ElvUI\
So I went into my Interface --> AddOns --> ElvUI --> ElvUI.toc
Open it up and it should look like this:
## Interface: 50400
## Author: Elv
## Version: 6.991
## Title: |cff1784d1ElvUI|r
## Notes: User Interface replacement AddOn for World of Warcraft.
## SavedVariables: ElvDB, ElvPrivateDB
## SavedVariablesPerCharacter: ElvCharacterDB
[color="#FF0000"]## OptionalDeps: Blizzard_DebugTools, Blizzard_PetJournal,[/color] SharedMedia, [color="#FF0000"]Tukui, SunnArt[/color]
## X-oUF: ElvUF
developer\load_developer.xml
libs\load_libs.xml
locales\load_locales.xml
media\load_media.xml
init.lua
config\load_config.xml
core\load_core.xml
layout\load_layout.xml
modules\load_modules.xml
## X-Tukui-ProjectID: -2
## X-Tukui-ProjectFolders: ElvUI_Config, ElvUI
Now delete the Blizzard_DebugTools, Blizzard_PetJournal, Tukui, SunnArt in ## OptionalDeps: line and it should work again. Will look like this:
## Interface: 50400
## Author: Elv
## Version: 6.991
## Title: |cff1784d1ElvUI|r
## Notes: User Interface replacement AddOn for World of Warcraft.
## SavedVariables: ElvDB, ElvPrivateDB
## SavedVariablesPerCharacter: ElvCharacterDB
[color="#00FF00"]## OptionalDeps: SharedMedia[/color]
## X-oUF: ElvUF
developer\load_developer.xml
libs\load_libs.xml
locales\load_locales.xml
media\load_media.xml
init.lua
config\load_config.xml
core\load_core.xml
layout\load_layout.xml
modules\load_modules.xml
## X-Tukui-ProjectID: -2
## X-Tukui-ProjectFolders: ElvUI_Config, ElvUI
Hope it helps! :clapping:
Make sure to make a backup of the .toc file before you change it!