I just put a Debian 12 on my old laptop (Thunderbird 102.12.0). Now I wanted to copy my Thunderbird-profile over from my Ubuntu desktop computer (Thunderbird 102.11.0).

I have tried it in two ways:

• Just copy the ~/.thunderbird folder over, and
• copy the contents of the active profile into the active profile folder of the laptop.

Between attempts I always stopped Thunderbird completely and emptied the profile folders.

I also checked the file ownership/permissions, and they look the same.

In all cases, I was greeted with the "Set Up Your Existing Email Address" screen, no mails or accounts were recognised. However, the address book is there.

Starting Thunderbird from the terminal, it says:

default value of option mesa_glthread overridden by environment.  
default value of option mesa_glthread overridden by environment.   
default value of option mesa_glthread overridden by environment.  
default value of option mesa_glthread overridden by environment.

Googling this uncovers nothing useful (to me, at least). I am stumped. Where could I look next?

I will be grateful for any hint.