You might see the Quickbooks error H505 when you try to switch into multi-user mode. It indicates that something is blocking the multi-user connection to your server. It usually occurs when one or more of your workstations have been set to the server.
You can resolve the QuickBook error H505 by performing the following step-by-step instructions.
Keep in mind that the computer that hosts a company file must be the only computer configured to host the multi-user mode. You have to disable the Host Multi-User Access feature on all your workstations.
To do this, carry out the steps given below.
Launch the QuickBooks software on the workstation where you see the error H505.
After disabling the Host Multi-User Access feature in all the workstations, continue with the following steps.
Open the QuickBooks software on the computer that you need to host company files.
Select the Utilities option from the File menu.