Don't export WMVs out of AE for later use. Use something lossless as an intermediate.
The free UT codec works well inside Adobe programs.
Correction. The file is being exported out of preimere not AE. I found out that it probably is a permissions error and not an Adobe error. If I export the file to the c: drive which is local I can import it into Media Encoder with no problems. If its exported to the server it is locked some how.
It's kind of a given that you shold be working entirely from local drives.
But my advice still holds. WMV is what you create once you're done. A lossless file for further use/transcoding is the better way to go here.