If the firewall is blocking the Delta application, this will give a generic connection error message of Error: 91. This error can show for any connection issue. This will show you how to allow the Delta application through the firewall.

If the firewall is enabled, it will be necessary to allow a number of programs through the firewall, in order to ensure that you have allowed everything through the firewall, please follow the steps, below:

If the ‘Allow another app…’ is disabled, click ‘Change settings’, then click ‘Allow another app…’.

4. In the resulting window.

5. Click Browse and navigate to the Delta installation directory.

6. Click on tpw.exe and click Open,

7. You will be returned to the previous window, but the Apps list should now show DeltaWMS.

8. Click Add.

There are a few other things you can try:

Repeat steps 4 to 7 for:

C:\Windows\System32\dllhost.exe (COM Surrogate)

C:\Windows\System32\msdtc.exe (Microsoft Distributed Transaction Coordinator Service)

If this is a 64-bit machine, repeat again for:

C:\Windows\ SysWOW64\dllhost.exe (COM Surrogate)

C:\Windows\ SysWOW64\msdtc.exe (Microsoft Distributed Transaction Coordinator Service).

Through the firewall, the following ports need to be allowed inbound and outbound. Ask your IT team to action this for you.