When you attempt to process Lockbox transactions in Web client, the user browses to the import file on a mapped drive and the file location is changed to C:\GPHTMLTMPE\1 and will not process. In fact, all configurator type files (Lockbox, Safepay, EFT, Payroll DD, Electronic reconcile) have an issue in Web client with the path. Please fix. The work-around is to use the Fat client.
Link to safepay product suggestion:
There are no future plans to change this in Web Client.