Unexpected token in message field

i am unable to parse a .proto file

it throws an error **('Unexpected token in message field: ' + tokens[0])**

can anybody say what does this error mean and how to fix?

Start with the .proto file that produces the reported parser error and trace where the message field is read, using the error text "Unexpected token in message field" as the entry point. Confirm whether the schema is invalid or the parser mishandles valid input, then document the cause and a reproducible fix.

Written by the indexing model from the issue text.