AX For Retail POS Error on startup: 'Retail POS cannot connect to a database. Try again later or see your system administrator'

In AX for Retail R2 (or earlier versions), upon clicking on a POS terminal with the intent of opening a POS session, you are slapped in the face by the lovely error 'Retail POS cannot connect to a database. Try again later or see your system administrator.' (see Figure 1 below)

Figure 1

This error (obviously since its stated as such) is because the system tries to open a POS session but cannot access the POS store's database. It then advises you to either try again or see the system administrator. The waiting game is because this could be because of a network issue and the terminal cannot connect to the DB. A DB connection is required for a store to be brought up as the one terminal one DB topology is no longer supported with AX for Retail after the 2009 release.

First off, since this message could be due to a number of reasons, check the Event Viewer's 'Application' Windows Log. It will save time and contains good stuff. As an example, if its the first time a user is attempting to get into a POS terminal and they got this error, the windows log may show: "Login failed for user 'CONTOSO\user1'. Reason: Could not find a login matching the name provided. [CLIENT: <local machine>]"

Solution to this error
If a user group of 'POS Users' is assigned to that DB and the user is not assigned to that group in the domain, they won't be able to get access. If you do add that user to the appropriate group in the domain, the user will need to log off their OS and get back in before they see the changes or else they will say 'It's still broken'.

Here are some steps the system administrator will do to resolve the issue if its not the above. Check that:

• The user has access to that database in SQL.
• See above example
• the POS configuration file is pointing to the correct DB
• Right clicking on the POS icon->'Open File Location' will take you to the config file if you have privileges.
• Then check the contents of the POS.EXE.CONFIG file.
• The <AXRetailPOS> node will have the DB server in the StoreDatabaseConnectionString attribute as 'Data Source=[THEDBSERVER];Initial Catalog=[THESTOREDBNAME]...'. Make sure these are correct.
• the Store DB server is up and running.
• the Store DB's SQL service is running and not stopped or paused
• the POS terminal machine can access the store DB
• Ping the POS store's DB server from the terminal with this issue
• If not able to, make sure the firewall isn't stopping the program from accessing the DB.