Hi @keyurpatel​ ,

Are you running any of your FME Server Services under an account other than local system?

I believe this problem is caused by a lack of permissions for this service account to the tomcat installation directory that FME Server is attempting to write temp files to during the upload process. To rectify this issue please go to C:\\Program Files\\FMEServer\\Utilities\\Tomcat and grant your service account write access to this Tomcat folder.

This is a known issue that has been fixed for FME Server 2021 so you should not need to explicitly grant these permissions in future versions.