Send button of emails not working anymore in pEp mode

For several users the pEp mode isn't working anymore, as some already pointed out at the Enigmail Forum

In my case this occurred one or two weeks ago. Before it was working without problems for several month. I already tried deactivating other plugins, reinstalling pEp-Engine and Enigmail - no success.

Enigmail 2.0.9
Thunderbird 60.3.0
debian 9.6
pEp JSON Adapter version 0.14.1 "(39) Gemünden". package_version="1.0.24"
pEpEngine version 0.9.0

I attached a (anonymized with XXXXX) logfile covering start, switching to forced pep mode and then sending the message (from 15:48:02)

Yes, normal permissions (-rw-r--r--)
I even renamed it and it was rebuild at restart. Also uninstalled pEp-Files and Enigmail and reinstalled everything again.

Probably helpful: I discovered that on my laptop everything is running fine. It's the same system and the same versions and has the same or at least a very similar thunderbird profile (i copied it from my desktop some months ago). But I discovered some differences:
1. pEp didn't generate a .pEp_management.db-shm and .pEp_management.db-wal on the defective desktop install
2. Enigmail on the defective desktop has the normal long enigmail menu (Decrypt/Verify ... [12 other points] ... About Enigmail).
On the working laptop it's the short Enigmail menu (key management and preferences)

EDIT: Ok, I think that's not helpful, the file came from another software opening the database and the missing pEp menue seems to be a consequence from the pep service not running.

It seems that the .pEp_management.db can't be generated anymore (even if I uninstall and reinstall enigmail and PEP completly). If I start pep-json-server manually, it is generated, but seems to be empty (4kb instead of 225kb on the working laptop install)

It seems that some weeks ago half of this forum thread got lost ... can you imagine how unprofessional this looks like from outside: You write a hotifx for a bug, which contains another bug and then the forum thread, in which a user reports and tracks down the bug gets lost on your server, while the bug still isn't fixed.

This is disappointing.