]> XSLT Map error: btm1050 🌐:aligrant.com

XSLT Map error: btm1050

Alastair Grant | Wed 4 May 2016
error btm1050: XSL transform error: Unable to write output instance to the following <output.xml>. Value cannot be null.
Parameter name: extension

You what now? This error was being produced when testing a BizTalk map that uses XSLT and XML Extensions (i.e. external assemblies). Debugging the map produces a slightly different error:

Cannot find a script or an extension object associated with namespace 'http://whatever/your/namespace/is'.

Where the namespace relates to the first called bound namespace for external assemblies.

This one took me a long time to figure out. In this situation there is a shared extensions XML file with a bunch of possible classes that are used in various different XSLT maps. The error was being produced by a reference to a class that wasn't bound or in use by the XSLT map - this class had been refactored to be abstract. The error I assume was happening when the class was trying to be instantiated - obviously something you can't do when it's abstract.

Removing these old class references from the extensions XML solved all the problems.


Breaking from the voyeuristic norms of the Internet, any comments can be made in private by contacting me.