Unable to search for mails, results in a "UID Search failed: Internal error"
The quick filter option doesn't work, always results in an error saying "no results" found. I tried enabling the global search and still the same issue persists. "UID Search failed: Internal Error"
Wšě wotmołwy (3)
Is that error message "UID Search failed: Internal Error" , the complete error message? If no please post the complete message.
What OS are you using? What version of Thunderbird are you using? Is this searching POP or IMAP mail accounts?
If Imap, do you only download headers or have synchronised mail for offline use? It is normal for imap to only download headers and retrieve the email when selected and storing in a temporary cache to facilitate viewing. Or have you synchronised folders for offline use to get a full download stored in Thunderbird. In which case you would be able to read emails even in 'Offline' mode.
Yes that's the complete error message. OS- Windows7 Thunderbird-45.2.0
Its IMAP mail account and its a synchronised mail for offline use as well.
I am guessing that there is some sort of error between the uid Thunderbird has and what is on the mail server.
IS that mail account small enough to delete and add again? or would synchronizing it take forever?
Does clearing the cache help?
On the toolbar 
> Options > advanced >Network and disk space and press the clear now button.