Ardour5 create backup copies

Hello, i made the dist-upgrade on my ubuntu studio and automatically upgraded to ardour5. The problem is that i cannot open none of my sessions correctly, it create a backup file every time…

Here is the message when i open an old session
"Ardour has copied the old session file

/home/tony/Scrivania/Lavori/Pop/Pop.ardour
to
/home/tony/Scrivania/Lavori/Pop/Pop-3001.ardour
From now on, use the backup copy with older versions of Ardour"

What do i have to do?, should i install ardour4 again. what would be the safest process to solve this problem?

We do not support the version of Ardour provided by Linux distributions. We support only the version that we build and make available via http://ardour.org/download

You haven't mentioned what actually happens when you try to open existing sessions. The most likely source of the problem(s) are plugins, notably those from CALF. There's a "safe mode (disable all plugins") button in the load session dialog that can be used to test this idea. Without more information, it isn't possible to say much more.

See also the comment at the end of this forum post/thread: https://community.ardour.org/node/14684#comment-46626

i’m sorry but i read always your answers and i asked here because i was a little concerned.
Actually it doesn’t seem to do nothing and work properly (for now), it’s creating a backup copy of the session and if choose one of these backups it create an other copy. It’s pretty messy because i’ve got files that weights gigabytes.
I thought that the problem was that i didn’t change the sample rate from 1024 to 512 like i usually did ,because i used to start jackd separately(now it seems not allowed anymore), but the problem remains.