ApexSQL Formatter fails to format code with UNION

ApexSQL Formatter fails to format SPs with UNION: when running formatting on long stored procedures (> 800 lines), getting the error "Line 456, Column:0, Position:0, Incorrect syntax near 'Union' ". The same stored procedure compiles and executes just great - so there is no syntax error!! I have noticed this issue with number of long SPs with UNION which compile and work absolutely fine! Obviously, there is a bug in syntax checking module of ApexSQL Refactor.

Does anyone know how to go around this bug or skip syntax check to apply required formatting?

Thank you!