I upgraded from EE 2x, to EE 3.5.16. I can see my primary site fine, but the other sites (both index.php and admin.php) say:
Your system folder path does not appear to be set correctly. Please open the following file and correct this: index.php
So I have checked all the usual - open_basedir looks ok (has not changed):
Folder permissions are 755 on site1.
Just to check the system_path, in index.php for domain2, I have added:
And this shows the correct path when I access index.php i.e.
I can access the domain2 control panel by first logging into the domain1 control panel.
I'm truly stumped. Everything was working fine with EE2 - what could have gone wrong?