Note: This applies to the scenario where you simply can not save and do not see an error.
When setting up a new register in ACDEV POS Remote Admin, if you are unable to save the configuration, confirm that you have receipt batches setup for that company & location. The receipt batch maps to the deposits that hit bank services. If you have a separate deposit for cash & check and then another is made from the credit card processor, then you would need 2 Receipt batch configurations (even if they go to the same bank account). Also keep in mind that you will need to create an AR distribution code in Sage 300 (or Accpac) that points to an POS Clearning Account and a second AP distribution code to points to a POS Clearing Account. You must create the POS Clearing Accounts in your chart of accounts, they are not out of the box in Sage 300 (Accpac).
Once you have Receipt Batches setup, you will be able to save your register configuration.