Hi @Td1!
Looks like you have a few errors happening so let’s address some of them from the top and see if this helps.
Here I would verify your installation of UE 4.26 and visual studio to make sure your binaries are in order.
Next few errors we see:
Did you upgrade (or downgrade) to a newer/older version of UE than you were initially working in and/or moved files to a different folder in your project? Here are some threads directly addressing those two errors:
Unreal Forums: Ue4 error malformed tag
Unreal Forums: How to fix : uasset has newer custom version of FortniteMain?
Working out of OneDrive is also a concern to look into, as OneDrive is not always static and can mess up projects (as I have found out the hard way).
And:
Are you building in a older version of Unreal than you had initially worked in? This error is extremely similar to the errors above. This might apply to the assets you have included as well.
There are a large number of assets with these 3 error messages, so I would make sure all of your files and assets are up to date or properly downgraded in your project.
Going through your log it seems there are specific assets these errors are pointing to, so I would make sure there are no leftover “ghost assets” left in those places specifically.
I apologize for the large chunk to look at, but I hope this helps!