Been developing a simple application using the Intuit Quickbooks SDK (Desktop), and everything has been working great for the last 3 months of development. I put development on hold for a couple of weeks, come back, and my app just won't open the Quickbooks (2015 Enterprise) data file. I can open it in Quickbooks, make changes and it works fine (file integrity is perfect - no errors).
When I initiate the QBsessionManager, I get an error: "Could not start Quickbooks". This happens whether Quickbooks is open, closed, multiuser or single user mode (makes no difference). As other forums suggested, I looked to see if there was another phantom version of QB opened in taskmanager - there is not. Makes no difference.
sessionManager.BeginSession(qbFilePath, ENOpenMode.omMultiUser)
MultiUser, SingleUser, DontCare open mode does not matter either. This code has been working fine for months - suddenly does not work at all.
In the QBSDKLOG.txt file, I see the following:
20150827.083322 I 10704 RequestProcessor ========= Started Connection =========
20150827.083322 I 10704 RequestProcessor Request Processor, QBXMLRP2 v13.0
20150827.083322 I 10704 RequestProcessor Connection opened by app named 'QBIntegrator'
20150827.083322 I 10704 CertVerifier The Authenticode signature validated OK.
20150827.083322 I 10704 RequestProcessor OS: Microsoft Professional (build 9200), 64-bit
20150827.083322 I 10704 RequestProcessor Current Process is elevated
20150827.083322 I 10704 RequestProcessor Current User is in AdminGroup
20150827.083322 I 10704 RequestProcessor Current Process is ran as Admin
20150827.083322 I 10704 RequestProcessor Current Process Integrity Level : 3000
20150827.083322 E 10704 RequestProcessor Unknown QBInstanceFinder error. File Name: "Q:\XXXXXXXXXXX.qbw" hr = 80070057
20150827.083322 E 10704 RequestProcessor Could not find or create an instance of QuickBooks using InstanceFinder hr = 80040403
20150827.083323 I 10704 RequestProcessor Connection closed by app named 'QBIntegrator'
20150827.083323 I 10704 RequestProcessor ========== Ended Connection ==========
The only thing I can think of (that changed) is that Windows 8.1 had some updates that somehow make Quickbooks 2015 Enterprise incompatible with Windows (Quickbooks has been plaqued with bugs like this for years, but Intuit forums do not indicate a new bug cropping up - so I'm at a loss).
I can only guess as to what this new problem could be.
NOTE: I'm developing in Visual Studio 2015 on Windows 8.1
There can be quite a few causes, but one that always gets me (and our users) -- if you are running QuickBooks as Windows Administrator, the Integrated Application (your app), must also be run as Windows Administrator and vice-versa. From the log you posted, it looks like your app is running as Administrator.
Like you said, it's always good to make sure there aren't any phantom QBW32.exes running, but if there are (and you're not running QB Enterprise) that usually gives a different error.
If that doesn't do the trick, this site has a list of 7 possible causes, but for me it's usually the first thing I listed above: http://www.clearify.com/wiki/view/381/error-80040408-quickbooks-doesn-t-start