This site requires JavaScript to be enabled


Dear Tricentis qTest users,

If you would like to submit a Tricentis qTest ticket,

please use this support request form.

Tosca Version
IncidentLookup using list
How can we help?

Solution Suggestions

Please enter your question to get suggestions.
Boolean Operators
OR or vertical bar symbol (|)
Finds a match if either the terms exist in a document (a union using sets).
Finds a match if both terms exist in a document (an intersection of sets).
NOT, minus (-), or exclamation point (!)
Excludes documents that contain the term after NOT (a difference of sets).
Asterisk (*)
The asterisk symbol performs a multi character wildcard search.
Percent sign (%)
The percent sign performs a single character wildcard search.
Quotation marks (")
Use quotation marks to search for an exact phrase with multiple terms.
For examples and more information look at our Knowledge Base: Advanced Search On The Support Portal

Error when referencing Excel file

This article describes a possible solution for the error "Exception has been thrown by the target of an invocation".

Another possible cause/solution to this error can also be found in the Knowledgebase article:

TC Reinstantiation Error MS Excel 2010


When assigning an Excel Template as a DataSource to a Template the following error is thrown:

"Exception has been thrown by the target of an invocation"





For a further analysis, please create the file "ToscaSupportInfo.txt".

Please make sure when creating this file, no instance of Excel is currently opened.

Find out how to generate this file here.


Then search the file for the error message below:

"Unable to access Excel.Application:  System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidCastException: Unable to cast object of type  "Microsoft.Office.Interop.Excel.ApplicationClass" to interface type 'Microsoft.Office.Interop.Excel._Application'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{000208D5-0000-0000-C000-000000000046}' failed due to the following error: Library is not registered. (Exception from von HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED))."


If this error is occurring in event that the library is registered correctly (which usually would be the case), then this is probably triggered by an additional folder in the registry named 1.8.
This folder is actually used for Office 2015. If office 2015 is not installed this folder should be empty.
It most probably has been added during an update of an office 2013 product i.e. Visual Studio 2013.


Before applying the steps listed below, please create a backup of your Registry entries and also contact your Systemadministrator.

  • Open the registry editor (regedit.exe)
  • Navigate to HKEY_CLASSES_ROOT\TypeLib\ and search for "Office.Interop.Excel".
  • Check for the node HKEY_CLASSES_ROOT\TypeLib\(guid)\1.8
  • If the node exists and the child nodes are emtpy, delete it and restart your PC




Tosca is the perfect solution

Optimize - Manage - Automate

Download Trial