Hello, I recently bought a MacBook Air 2024 with G3 chip (Sonoma 14.6.1) and used Time Machine to transfer all the data from my previous Apple MacBook Air from 2015 (Mojave 10.14.6) to the new computer. This also transferred my Thunderbird profile folder. It has the extension .default and an 8-digit combination of letters and numbers in front of it. Since the old version of Thunderbird no longer ran on Sonoma, I installed Thunderbird 115.15.0 and then opened Thunderbird on the new MacBook Air. Since then, Thunderbird has been taking an extremely long time to open (much longer than on the old MacBook Air with Mojave. Yesterday I updated to 128.2.0esr, which didn't help either. I deleted a deactivated extension in the add-ons, so that there are now no extensions, only a few dictionaries that I deleted as a test, which also did not bring any improvement. Switching off the hardware acceleration, clearing the cache and changing the themes did not improve the situation either. With the themes, I can only switch between dark, light and system theme - automatically. I checked and made sure that Thunderbird actually loads the .default profile folder from my old computer as the active profile. However, Thunderbird has also automatically set up a second profile with the extension .default-release. Could this be causing the problem? My active profile folder has a size of 15.21 GB and the new .deault-release profile folder has 18.6 MB. Both profile folders are located in Library/Thunderbird/Profiles I am quite desperate and hope that someone can help me. Thank you very much!