question on editing multiple transactions

[Jack]

I'm curious about the current state of editing multiple transactions in  
the ledger, in master branch.  I know there are some restrictions, but  
I don't remember what they are, or if they are actually written down  
anywhere.

I have several transactions with the same category, which was  
incorrectly set on OFX import.  I can select more than one of these  
transactions, and select edit, but the category field is disabled.  In  
a 5.1. appimage, I can select and edit multiple transactions, and can  
set the category dropdown, but am still not able to save the changes  
(the OK button is disabled.)

Thanks for any hints of pointers to why this might be.

Jack