The message is complaining about line 148 of the pepXML file which look like this:
<annotation protein_description="40S ribosomal protein S14-B OS=Saccharomyces cerevisiae (strain ATCC 204508 / S288c) GN=RPS14B PE▒"/>
Apparently this protein entry in your database has a non-ascii character in the descriptions of this protein. Can you please share this database so I can examine this protein entry or can you check it in the fasta file? I think the problem might be somewhere upstream of the error but would need to do a bit more digging to confirm. Also if you are able, please compress and share the data from the whole analysis you've done so I can trace where the failure occurs.