Merge_metaphlan_tables.py error after fix_relab_mpa4.py

Hello, I have applied the fix_relab_mpa4.py to my profiled.txt data (run with version 4.1.0 and with the unclassified reads tag) to correct the abundances and taxonomy. However, when I then run the merge_metaphlan_tables.py it generates an error:

pandas.errors.ParserError: Too many columns specified: expected 5 and found 4

The only thing I noticed after running the fix_relab_mpa4.py function is that the UNCLASSIFIED category has disappeared from the corrected files, so I wonder if that has something to do with it.

Thank you