I've recently moved several sites from Drupal 7 to Backdrop without a problem, for the purpose of moving CiviCRM systems. However, at Civihosting.com I can install Backdrop OK, but after installing CiviCRM I immediately get 'Unable to reach the server' messages, CiviCRM is unusable (Backdrop is fine) and I haven't been able to figure out why. So I set up a subdomain there and installed D7 and CiviCRM and it worked. Which isn't so surprising as they've been running like that for a year or so. The only clue I have found is a message in the error log that says 'my.kewguild.org.uk [Sat Sep 14 09:43:37 2024] [error] [pid 19034] mod_negotiation.c(1286): [client 104.28.86.98:27213] AH00687: Negotiation: discovered file(s) matching request: /home/kewguild/www/my/civicrm (None could be negotiated).' which frankly I don't understand. The common factor of failure is, of course, something in the civihosting.com setup, but I am surprised by this. Has anyone any clues?
The fix is to add the following to the .htaccess file
Options -MultiViews
and this is also discussed here in this very forum.
Thanks to David at Civihosting!