In the past weeks I have been experiencing HUGE problems with global search, which I had been successfully using for years. The search function now has an erratic behaviour, in that - depending which search term I am using - it will only find a few (but not all) messages containing such term, and will miss certain folders altogether, although global search is enabled on them. Sometimes it will miss some folders, some other times other folders. The behaviour for each search term is however consistent, in that for a single search term it will always yield the same (incomplete) result. All messages are on the other hand correctly identified if I perform the local search within a single folder, which I imagine means the messages are indexed correctly. I did delete the global-messages-db.sqlite file as instructed, but this made no change. My message database is large (over 800k mb), and I have approx 20 different folders. They are all however essential messages, so I cannot reduce its size in any way. Any suggestions? I really really need to get this sorted. ps I initially thought this malfunctioning had been caused by the update to the newer Thunderbird version, however I reverted back to version 52.9.1, with no improvement whatsoever. Does a 64bit version exist?