I’m having this issue also. It started showing after I moved my String Table to another folder so it seems to be caused by references not being updated correctly.
Moving the string table back to the old folder resolved the issue for me - but so far I haven’t found a solution where I can actually move the String Table to where I want it to be.
Scanned my blueprint folder for the missing stringtable with path (e.g. /Game/Assets/CommonWords.CommonWords) using Notepad++. BP’s containing the path are listed
Had a detailed look at the BPs to identify uses of any on the key words and updated / removed those manually
In my case, the badly updated assets were either:
Structs definitions (that always have a default value assigned, which in my case was refering to the missing string table
BPs with ‘loose’ nodes refering to the missing string table
Well… I was searching directly through the .uasset files. Notepad++ is perfect for that because it allows you to look through a whole folder of (binary) files all at once. No editing (because that immediately makes them unusable) but just to help identify where the references show up. This worked for me for blueprintes. In C++ you can identify references in a more direct way I presume.