Comment 6 for bug 1975340

Greetings!

I had the same problem. And finally resolved it with these steps:

1). Added myself into boinc group for starting Boinc Manager:

sudo usermod -a -G boinc $(whoami)

2). Added Boinc Client into startup applications:

sudo systemctl enable boinc-client.service

3). Finally reboot system:

reboot

After rebooting both and Manager and Client work. It is necessary to add project and configure application settings.