The main cause of this issue is that there is one or more broken Tests in the template. This can be found in the following way:
Open Workflow Maintenance
Select the relevant case type then locate the template for the document you need to fix
Click the Word icon to open the template
Look through the document looking for any Tests used, these will have an IF, ELSE, and END section per test ( the ELSE part is optional so if not present this may not me an issue)
Check for any of the tests that are missing either the IF or END section
For any test missing a section remove what is there and re-add the test from the Field Selector
Repeat the above steps for any further broken tests you find in the document
Exit Word and Save the template
If there are any further issues or if you do not have access to Workflow Maintenance please raise a new case online and reference the title of this article.