in Ardour6, if I close a session and open another recent one, it gives me these errors:
ERROR: JACK: Cannot callback the server in notification thread!
Cannot initialize session/engine: Port registration failed. ---ERROR: unable to create port 'MIDI Clock in': failed constructor
Instead, if I turn off Ardour and restart it by opening the same session first, then it opens it correctly.
This is the first time this has happened, it has always worked, but I have no idea what could have happened.
How can I solve?
[I use Ardour 6.9.0 “After Bach” (rev 6.9) Intel 64-bit - debug on Ubuntu 18.04]