Well, I tried three things out now, all three tests fail, if the IE-addon is deactivated and succeed, if the IE-addon is activated:
1. In my application (don't laugh, it is VB6 legacy code ) my failing code looks like this:
Dim Pdf1 As Object
Set Pdf1 = Controls.Add("AcroPDF.PDF.1", "AcroRead")
Then Controls.Add fails with the message that a new instance of AcroPDF.PDF.1 could not be created or activated. The error number is 743.
2. During Debugging anything, I write the following text in the Immediate Window:
CreateObject("AcroPDF.PDF.1")
This call throws an Exception with the inner exception "The ActiveX-component could not be created"
3. The Acrobat XI SDK-sample AcrobatActiveXVB:
In InitializeComponent the following call throws an InvalidOperationException:
CType(Me.AxAcroPDF1, System.ComponentModel.ISupportInitialize).EndInit()
The inner exception says "The call of a COM component returned HRESULR E_FAIL" The Errorcode is -2147467259.
Hope, that helps...
Best regards,
Thomas