All email disappeared from folder after trying to repair folder. TB has been extremely dysfunctional to the point where I haven't been able to use it at all. I have been trying to diagnose the problem and following steps here https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems as previously suggested. I tried repairing and all mail has now disappeared, further compounding the dysfunctional behaviour of TB and the daunting task to try and get TB fixed. Help/advice much appreciated. 128.3.3esr (64-bit)