Once upon a time I opened the homepage of my website and was redirected to nowhere.
The URL was something like
I was very surprised.
So I started recovery works on the website. Usually, hen I see any matters with website first I clean the cache manually - remove everything in /tmp folder except the /tmp/dump. Second stage is to upgrade SPIP to the current version in it branch.
I did all - cleaning and upgrading to 2.1.19 but it didn’t help me. The .htaccess was off and website still redirecting me without /plugins and /squelettes folders. This means that php files works correctly and the matters could be only in database.
I check the database (analyze table) with PhpMyAdmin and some tables were corrupted (spip_meta and some other). I did the repair operation and the website began to work.
Hope this story would help you.
Another SPIP solution story you could read here:
SPIP. Could not add a file to the article/section