This issue arises due to incorrect mapping of the drive. To resolve it, you need to configure the settings on both the client and server PCs.
In Client PC:
Go to the UBS landing page.
Click the setting icon next to the company name.
Check the Inventory & Billing directory.
Make sure it is pointing to the mapped drive correctly. e.g.: y:\UBSSTK2015\company.
In Server PC:
Go to This PC.
Check if the file is in this folder.
If the folder is not in, double-check the directory mapping.
If the issue persists, raise a new case.