This indeed does sound strange. Typically if you reset a workflow I would expect it to revert to the default compression next time. And at least with zip or parquet KNIME seems to be happy with using both. Cf. also this entry:
Question is if you reset a workflow would it then run Ok.
If a workflow is stored with data in it you could:
- export it into a knwf file without data stored
- rename the original WF
- import the stored one
Now you should have a working WF.
Then could you tell us more about your system and setup and versions. And maybe provide a fresh log file set to debug. Maybe someone from KNIME then can weight in.