I'm not sure, but try the above, then exit SCID, then restart it and see if that works. I read about a bug like this, somewhere, but do not remember the details.
How to make a SCID repertoire database?

The repertoire db feature is broken. Use a tree mask instead.
I want my money back!...
Oh, wait......
I cant get it to work.
I make a database, and set the icon for white openings
I click PLAY/Training/Openings
I get a "Open first a repertoire database with icon/type set to the right side' error.
What am I doing wrong?