We recently updated Apache following multiple security issues corrected in the last versions.
One of the patches in this update introduces a new behaviour in Apache on htaccess directives.
Every directive "Allow or "Deny" followed by a comment with a hash will trigger an Apache error (500).
This particular change introduced by the Apache Foundation corrects multiple security issues.
Your website could be impacted by this change, to correct it, move or delete the comments following those directives (Allow/Deny)
See below the issue and how to resolve it:
Deny from a.b.c.d # ip a.b.c.d blocked
# ip a.b.c.d blocked
Deny from a.b.c.d
Any other Error 500 is not linked to the update.
For more information, here is the apache changelog:
We remain available for any support you may need.