I assume Freezing in Ableton works the same as it does in all other DAWsâ€”the track is bounced down to an audiofile, and when it's un-frozen it resumes the live playback of the virtual instrument & plug-ins on the track.. If that doesn't sound like the Frozen playback (or doesn't sound at all, as in your case), then my first guess would be that some live component of the track must have changedâ€”maybe a missing V.I. or FX plug-in, or a missing instrument patch, or samples that have been moved and the V.I. is no longer seeing them..? Or maybe some routing/bussing has changed that affects the live signal path (like V.I. multi-output routing to a now-muted Aux, or sidechain control of a gate or compressor in the track routed from another now-muted (or Frozen) track) but not the Frozen file? Can you play that track's sound live from the keyboard?
I'll link this thread to one of our most recent Live (10) coursesâ€”maybe another Live user will recognize the issue and weigh in with further suggestions..