Why QuickBooks Can’t Switch To Multiuser Mode

Query: We have QuickBooks Pro 2015 and recently updated the workstations. Now, when we try and open the company file on more than one workstation we get a QuickBooks H202 error. So, you are able to access QuickBooks when you are in the single-user mode, but as soon as you move to multi-user mode the screen displays an error and you are no longer able to use QuickBooks as good as...