Subsites no working after migration

Hi,

My multisite consists of 3 subsites.
I migrated my multisite from https://www.example.com/testsub/ to https://www.example.com/.

Now, the primary site is working correctly, but I cannot access the subsites(i get the 404 page) and subsites’ admin panel(redirects to primary site admin).

I replaced all /testsub/ strings from .htaccess, wp-config and databases.

I am using a custom theme, but it also doesnt work in Twenty Fourteen.

Any ideas?