Error: Unable to get property 'toString' of undefined or null reference

ISSUE

When accessing a Nintex form, the following error occurs:

RESOLUTION

Verify that all Form Variables, Rules, and Controls which are utilizing runtime functions are properly configured and use the correct syntax.

ADDITIONAL INFORMATION

This error generally indicates that there is a runtime function which is configured incorrectly, such as with a missing parameter, or utilizes incorrect Syntax.

 

For Example the runtime function DateDiffDays:

 

Correct Syntax: DateDiffDays(StartDate, EndDate)
Incorrect Syntax: DateDiffDays(EndDate-StartDate)

 

In the incorrect syntax the runtime function does not detect a second parameter which will yield this error.