I am sorry about my bad english, I am from the Czech Republic.
I put into operation of track in Audacity 2.2.1
I record singing mono (AKG P420 with phantom power, which I switch on external sound card.
I save project.
When I will open it again, I can not open it or I can not save it to WAV.
Alone, If I apply it to intrument tones or just singing, it does, but the microfone does not work together.

Thank you for any answer.

The current version of Audacity is 2.3.0 (2.3.1 is due to be released later this month).
The current version is available via the Audacity website: Audacity ® | Download for Windows

Why not? What happens?

I don’t understand what you mean.