You've got double slashes in your path.
set @OutputFileName = 'C:\\tracefiles\SQL_Performance' + '_' + convert(varchar(20), getdate(),112) + Replace(convert(varchar(20), getdate(),108),':','')
The first error is 'could not create trace file'.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability