SummaryWhen publishing a workflow, the following error might occur: Error publishing workflow. Workflow XAML failed validation due to the following errors: Activity 'FormatString' has XX arguments, which exceeds the maximum number of arguments per activity (50). Activity `FormatString` has 59 arguments, which exceeds the maximum number of arguments per activity (50). (...). The remote server returned an error: (400) Bad Request.
SolutionSharePoint Workflow Manager has a limitation of 50 references for a 'FormatString' Activity. This can surface either in Log to History Actions (if you don’t reach the character limitation first) or by trying to render those in an action such as a "Send Email" or "Assign Task".
Reduce the number of field entries that you are trying to render into and the error should disappear and the publish should work.