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"Cannot open the database" message is received after TaxCalc is installed on an additional machine

This message may be shown when trying to connect to a remote database from a workstation:

Cannot open the database. The database on server...

Note: The blank area in the error dialog above will have a machine’s name listed.

If this happens then it is likely an issue with the firewall settings on one (or both) machines.

Amending your Firewall

For TaxCalc to connect to the database, the following ports need to be open through your firewall:

  • 5432 or 5433 (If running version 4.0 or later of TaxCalc)
  • 3838
  • 6178

Note: Before getting to grips with firewall ports, you can try temporarily disabling the firewall entirely.
However, this test is entirely at your discretion – there is always an element of risk when disabling a firewall, even temporarily.

If the database connection can be made while the firewall is down, it is definitely a firewall problem. Once the firewall is re-enabled, opening the ports listed above should solve your connection problem. Guidance for your specific firewall should help you with correctly opening these ports.

Related articles

Firewall configuration

"Database connection details not found" when adding a new workstation to a network version of TaxCalc

How do I configure the firewall for the network version of TaxCalc?