It's v2.1 of Steinberg The Grand.

 

Have you tried possibly playing around with your buffer settings? Does this happen with all VSTs or just the one you mentioned? FL Studio tends to have too many bugs in my opinion. I constantly experience crashes with anything from scanning VSTs to opening a VST3 plug-in. I also think the mixer is seriously overdue for an update and the lack of a freeze track option is a joke. I really like it for composition because it has a smooth workflow with few snags but for serious work I prefer other offerings. I fantasize of a company combining their MIDI editing implementation with the advanced features of Cubase. Now that would be a DAW!

 

I have to sample TheGrand2 to kontakt since i can't live with a DAW that hangs forever when i pause/resume the song.
And then press the stop button many times to reset song position so that the song plays from the start. I have to wait a few minutes before the freeze is over.