When starting Quickmap, you may get this error:

InvalidCastException: Unable to cast COM object of type ‘QCONTROLLibV2.QEncryptClass’ to interface type ‘QCONTROLLibV2.IQEncrypt’. This operation failed because the QueryInterface call on the COM component for the interface with IID ‘{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}’ failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)). in SurveyHelper.GSPP()

It may also be accompanied by this data:

Custom.Software.Quickmap.Helpers.SurveyHelper.GSPP(String sFile)

System.StubHelpers.StubHelpers.GetCOMIPFromRCW(Object objSrc, IntPtr pCPCMD, IntPtr& ppTarget, Boolean& pfNeedsRelease)

QCONTROLLibV2.QEncryptClass.Encrypt(Int16 seed, String Value)

This happens because the install of Quickmap was interrupted, leaving Quickmap with enough files to look like it should be able to start, but not quite.

Typically this is caused by the antivirus program interrupting the install.

The fix for this is to rerun the Quickmap setup, it should just pick up from where it left off – do not uninstall Quickmap before you do this, otherwise you’ll encounter the same problem again.