Email search error

[ekevu123]

When in Roundcube, I get this error when I open a folder:

Server Error: UID THREAD: Internal error occurred. Refer to server log for more information. [2025-04-01 05:11:13] (0.194 + 0.000 + 0.193 secs).

There is nothing in the logs, though, neither for the Roundcube app, nor for the server.
The email logs are a bit verbose, what element are we looking for? Then I can check.

I believe this issue might be related to the full text search of e-mails, which I have activated.

By checking the email logs even further, I got similar error messages, although not related to the action I was performing:

Error: Mailbox INBOX: Transaction commit failed: FTS transaction commit failed: backend deinit
Error: fts_solr: Indexing failed: connect(127.0.0.1:8983) failed: Connection refused
Error: Mailbox INBOX: Precache for UID=1001 failed: Internal error occurred. Refer to server log for more information. [2025-04-01 05:22:17]

[avatar1024]

Hi, did you check this, this and this? I got the similar errors when trying to run the indexing but after a few retry it works.

I tried to index email mailbox separately (by running the command inside the rebuild-index.sh for each mailbox separately) and identified which one caused the problem, then I had to open/read the problematic folders with a mail client, and then the index worked.

Given this feels like another duplicate, @staff, there might be something up / to improve with how the indexing is handled.