Recorded cubase 11 Audio tracks disappeared

using cubase 11 windows 10 64 bit - I had previously recorded long time audio tracks, the next night their content was no longer there, but their allocated tracks and identifications were still present.
A hint might be the last night when all was ok adding vocaloid stand alone software and a dedicated track for it.

Hi and welcome to the forum,

Can you hear the sound? Can you see the waveform? Can you see the meters? Is vocaloid (probably used as ARA) applied to the affected Audio event(s)?

it could be that something renamed the audio files outside of Cubaseā€¦