Can you provide more information on why you think it will not allow you to backup to a NAS?

Are you trying to do a network backup or a local backup?

What, if any, message are you getting? When?

I am trying to back up the database to a NAS over our peer network.

When I exit, TS asks me if I want to make a backup. I click yes, and I get a dialog box offering me the choices of:
1) Back up the database on the server
2) Back up to a file. This choice informs me that I can back up to any location to which I can browse. Since I have been backing up to the NAS in TS2016, the NAS is preselected.

When I click OK, I get an error message which says, "Backup files must be saved on a local drive."

Is this NAS path a mapped letter drive? Or a UNC mapped drive?

I believe it is UNC mapped. The path shown in the backup window begins with \\Seagate-D2\. The Seagate-D2 is the NAS.

Very good. Could you go ahead and test mapping the NAS to a drive letter and see if that makes a difference in the backup routine?

I attempted to back up to this file: T:\9-22-2016.tbu (T is a mapped drive). Same results. Error message: Backup files must be saved on a local drive. I understand that TS2017 is using Firebird, which is an SQL database. I have the same problem with TimeMatters, which uses Microsoft SQL Server as its database engine.

Is the NAS drive connected to the server or your local workstation? What is the path from the server? I seem to recall that backup locations have to be local to the server.

Well, then the quickest/easiest fix is to let it back up locally, and then have a process to automatically copy that backup off to a second location/NAS.

NAS is not connected to either. It has its own network IP address. Backups apparently have to be local to the server, which violates fundamental backup principles. It should be easy to backup to another target that is not on the server. I can do it in Quicken, and I did it in previous versions of Timeslips. I should not have to backup to the server and then copy the backup to the NAS. I know it's not your fault. It is just maddening that in the 21st century software designers are making it difficult to make backups that are not on the machine that has the source file on it. I have to do the same thing with TimeMatters, and I have been complaining to them about it for several versions now.

This problem is not your fault, and your solution appears to be the only one at this point. I should not have to do all that. I could backup to the NAS with previous versions of Timeslips with no problems or complicated solutions to a problem that should not exist. Backups are supposed to be easy to make, and they should be made to a location not on the server. What is with these software designers? Backup experts tell us to backup to a remote device and get backups to a different physical location than that of the source device, but software designers make that as difficult as possible, instead of making it as easy as possible.