Just so you know that you are not the first to encounter this problem …
Of the topic threads on this issue, this thread had the most activity …
SU2017 New Install with Load Errors on Plugins
Several of the participants (in that thread) were able to create a temporary “test” user account, on their computer, that could load the shipped extensions without the RBE/RBS file read errors.
This points to their usual user account as having something corrupt.
My aunt once had some malware corrupt her user account and some things would not run, etc.
I had to copy all her files, bookmarks, settings (etc.) and email archives to the public folders, then delete her account, and recreate it. Lastly copy all her “stuff” back to where it belonged.
I mean choose from the printable characters in the ASCII set when creating a Windows user account.