Problem with solr working, but not indexing

[TG Servers via dovecot]

Hi, I have setup dovecot 2.3.5.1 with solr 7.7.1 Everything seems to be working so far except that solr doesn't index a single message. Solr is running, the web api can be accessed, I see the dovecot core there, but with zero docs. If I trigger a "body" search from Thunderbird solr is responding and searching, but hitting 0 of course. Looks like that : 2019-04-14 19:57:42.789 INFO  (qtp898557489-40) [   x:dovecot] o.a.s.c.S.Request [dovecot]  webapp=/solr path=/select params={q={!lucene+q.op%3DAND}body:foobar&fl=uid,score&sort=uid+asc&fq=%2Bbox:925efe067ac8a35ce1430000828c97da+%2Buser:x...@xxx.net&rows=2&wt=xml} hits=0 status=0 QTime=2 Everytime a new message comes in indexer-worker is working but indexing 0. Looks like that : 2019-04-14T19:39:36.887817+02:00 riot dovecot: indexer-worker(x...@xxx.net)<31697><3pDsLlhws1zMewAAgoyX2g:vb2mNFhws1zRewAAgoyX2g>: Indexed 0 messages in INBOX A "doveadm fts rescan" just brings up this message : "Fatal: Unknown command 'fts', but plugin fts exists. Try to set mail_plugins=fts" My dovecot settings are : plugin {     sieve_plugins = sieve_imapsieve sieve_extprograms     sieve_before = /var/vmail/sieve/global/spam-global.sieve     sieve = file:/var/vmail/sieve/%d/%n/scripts;active=/var/vmail/sieve/%d/%n/active-script.sieve     ###     ### Spam learning     ...         sieve_pipe_bin_dir = /usr/bin     sieve_global_extensions = +vnd.dovecot.pipe     fts = solr     fts_autoindex = yes     fts_solr = url="" class="moz-txt-link-freetext" href="http://localhost:8988/solr/dovecot/">http://localhost:8988/solr/dovecot/ debug     ... } I don't know what to do or what I am doing wrong because solr is responding as said. Also the data directory of the core is empty. If I should provide more information please tell me which, it's my own server so I have access to everything Can anyone please help with that?? Thanks.