Binder connection to editor broken

I opened a project I’ve been recently working on and found that clicking a file name in the Binder does not load that file into the Editor.

I’ve checked one (1) other project and it still works properly.

I tried rebuilding the indexes and that did not repair my problem.

I’m running Scrivener 3.1.5 (12258) on an MBP 15" running OSX 10.15.6

I attempted to attach the project only to receive a ‘File too large’ error.

How can I fix this?

Note: I found a backup copy in yada-yada/Application Support/Scrivener and it works. Both the broken and pre-broken are on Dropbox.

Broken at … stciv?dl=0
Pre Broken at … jIxCa?dl=0

Have you checked Navigate->Binder Selection Affects ?

No, I had not. Thank you. It was set to ‘None’.
Frankly, I don’t understand ‘Binder Affects’, so I’d best read up on them.

Thanks again.

Section 12.2.3 in the manual. It’s a potentially confusing but very useful feature. Lets you lock one pane of the editor while you revise in the other, shuffle to your heart’s content in the Binder without messing up the editor, all sorts of useful things.