Symptoms:
Pre-Processing can result in failure when handling files from a UNC path.

Explanation:
In an SDL TMS multi-server environment, when using a UNC path for storing and managing files, Pre-Processing fails sometimes during the extraction of the translatable content. This is due to the impossibility to move the temporary extracted file to the final location (for example, to the TC\SRC folder) because Windows® caches network paths. This caching prevents SDL TMS from accurately determining whether a file exists at a certain time, either because the file has been recently deleted but it is still reported present, or the file has just been copied but it is still reported absent.

Resolution:
To work around Windows' caching of network files, if the operation fails, then TMS considers the UNC file does not exist. Also, whenever a temporary extracted file has been generated and has to be moved to the final location, then the already existing target file (if any) is overwritten.