"Cannot create/shadow copy 'VariousFileName' when that file already exists" is a .NET problem with a quick cure.
Try this first:
Solution #1 -- of Cannot Create/Shadow Copy when that file already exists
Solution #2 of Cannot Create/Shadow copy 'xxx' when that file already exists -- web config solution
Solution #3 - w3p or aspnet - cannot create shadow copy when that file exists
Alternate Solutions to Consider