Sounds like there could be more than one host of Reckon Accounts (Quickbooks) on the network.Please check to see if the non-server computer is hosting, in Reckon Accounts, go to File > Utilities. If you see Stop Hosting Multi-user Access, click it. Then try to open the file.
If issue presist, please check the following article.http://www.quicken.com.au/kb/issue_view.asp?ID=4682
If all of them showing 'Host multi-user Access', then they are not hosting.
On a network, there should be one host, normally it's the server computer.You need to find out which computer is the host.Once you find the host, you can try to stop hosting, then re-host, then try to open the file again.
When you say 'the problem of parallel sharing still persists', I assume that you have problem with multi-user opening the file at the same time.
Are you still getting error 6073, 816 when trying to open the file?
You can also try using network mapping, instead of UNC.Map the data file folder to the three workstation using the same Letter.Open the data file from the host first, then try from the others.
Please email your customer ID to [email protected] with attention to: Deny.
I got your email with the attached diagram of your set up.Sounds like the next step that you can try is to: