A friend of mine, Dave Sanford, passes this along:
We experienced an issue when installing the Quickbooks client upgrade to QBEv14R5, just last week.
We had 3 users in one office and 4 users in another and the first 3 went through no problem, then the other 4 threw the error (sample below) no matter what we did. The install went fine, but then just died whenever you tried to open a company file, with the error message.
Name: \\server\quickbooks file name
Description ND File
//This is QuickBooks configuration file. It exists while users are connected ..//to a company file. Do not delete this file yourself. QuickBooks may not .. // operate correctly IF you manually delete this file.
[NetConnect] ..ServerIP=192.168.x.x..EngineName=QB_Servername..ServerPort=55358 File path = (location of file) ServerMode=1
We were using the QBE V14 R5 installer, and performed all the possible resolutions we could think of, including recreating and verifying the .ND files, coping the company files to a local machine to isolate any network/server issue, running the QB built in File & Network diagnostics and the QBInstallDiagnosticTool on the clients, same results.
Finally, one of our techs received the “DbProviderFactories section can only appear once per config file” error when trying to open Quickbooks, and searching for that error led him to this link:
We then checked all of the machines we had installed the upgrade on and found that all of the machines with the error indeed did have the extra DbProviderFactories empty element in the Dot_Net_v4… machine.config file. Once we commented out the extra element, all of the machines were able to boot QBE and access the company files without issue.
I then installed on my laptop, got the same error and applied the same fix, after which I could proceed without error.
The odd thing is that it seems some machines have the extra element in the Dot_Net_V4 file and some do not… yet we cannot identify any difference in the level of Dot_Net updates applied – they are all running Win 7 Pro – and none of these machines, including my laptop, have anything to do with Visual Studio of any version… go figger!?!
In the event, just wanted to let you know as maybe it will help others that encounter this issue in the future?