The value for your FileFolder path makes no sense to me. Why are you adding ThisWorkbook.Path to your folder's path?

Are you working from a sharepoint site? I don't know that file/folder paths would work for such. If it did work, then something like:
FileFolder = "\\sptd.sabert.net/sites/op/olt/Production Supervisors/HouseKeeping/Completed_Checklist\" & Range("E4").Value2 & "\"