Ich erhalte die Fehlermeldung -2147220472, wenn ich versuche, eine Verbindung zu Quickbooks herzustellen. Die Anwendung wird von einem Windows-Dienst ausgeführt. Die Protokolldatei sieht wie folgt aus:

I   8788    RequestProcessor    ========= Started Connection =========
I   8788    RequestProcessor    Request Processor, QBXMLRP2 v12.0
I   8788    RequestProcessor    Connection opened by app named 'QBWatcher'
I   8788    RequestProcessor    OS: Microsoft Professional (build 9200), 64-bit
I   8788    RequestProcessor    Current Process is elevated
I   8788    RequestProcessor    Current User is in AdminGroup
I   8788    RequestProcessor    Current Process is ran as Admin
I   8788    RequestProcessor    Current Process Integrity Level : 3000
I   8788    RequestProcessor    Previous instance of QB is going down..! Wait and retry to get a new instance.
I   8788    RequestProcessor    Previous instance of QB is going down..! Wait and retry to get a new instance.
I   8788    RequestProcessor    Previous instance of QB is going down..! Wait and retry to get a new instance.
I   8788    RequestProcessor    Previous instance of QB is going down..! Wait and retry to get a new instance.
I   8788    RequestProcessor    Previous instance of QB is going down..! Wait and retry to get a new instance.
E   8788    RequestProcessor    Could not find or create an instance of QuickBooks using InstanceFinder
I   8788    RequestProcessor    Connection closed by app named 'QBWatcher'
I   8788    RequestProcessor    ========== Ended Connection ==========
I   8788    CertVerifier    The file does not contain an Authenticode signature.

Das funktioniert manchmal, aber ich sehe kein Muster. Was könnte das verursachen?

Kurz gesagt, der Code, mit dem eine Verbindung hergestellt wird, lautet wie folgt:

qbxmlConn.OpenConnection2(filename, "QBWatcher", QBXMLRP2Lib.QBXMLRPConnectionType.localQBD);
QBXMLRP2Lib.IAuthPreferences qbAuthPrefs = qbxmlConn.AuthPreferences;                                   
qbAuthPrefs.PutPersonalDataPref(QBXMLRP2Lib.QBXMLRPPersonalDataPrefType.pdpNotNeeded);
qbAuthPrefs.PutUnattendedModePref(QBXMLRP2Lib.QBXMLRPUnattendedModePrefType.umpOptional);
ticket = qbxmlConn.BeginSession(filename, QBXMLRP2Lib.QBFileMode.qbFileOpenDoNotCare);