When you try to unit-test a map by using a script functoid of a custom assembly, the unit test is unsuccessful. Additionally, you receive the following error message:
Microsoft.BizTalk.TestTools.BizTalkTestAssertFailException: Transform Failure.
Cumulative update information
For BizTalk Server 2013 R2
The fix that resolves this issue is included in Cumulative Update 3 for BizTalk Server 2013 R2.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about service pack and cumulative update list for BizTalk Server.
Learn about BizTalk Server hotfixes and cumulative update support.