Missing or corrupt gateway files.
Gateway files, such as current.apt, master.glm, new.prt, etc...are pointers to the actual data which exists in similarly named folders inside the PVData folder (for example: current_apt, master_glm, new_prt, etc...).
When performing a task in the software, if the gateway file is missing for a file it is trying to access and it attempts to create the file, if it detects the PVData files exist for that file, it will present the error.