I am building a simple flow that sets a checkbox on a related custom object record whenever a user record is set to inactive.  I can't get this to work.  I recieve the following error every time.

 "Unable to Access Page The value of a parameter contains a character that is not allowed or the value exceeds the maximum allowed length. Remove the character from the parameter value or reduce the value length and resubmit. If the error still persists, report it to our Customer Support team. Provide the URL of the page you were requesting as well as any other related information."

That error doesn't relate to anything I am doing.  I am not passing any values from the User record to my related record.  I am simply updating a checkbox on that related record.  

Is there some salesforce limitation when dealing with the User object?

I am building a simple flow that sets a checkbox on a related custom object record whenever a user record is set to inactive.  I can't get this to work.  I recieve the following error every time.

 "Unable to Access Page The value of a parameter contains a character that is not allowed or the value exceeds the maximum allowed length. Remove the character from the parameter value or reduce the value length and resubmit. If the error still persists, report it to our Customer Support team. Provide the URL of the page you were requesting as well as any other related information."

That error doesn't relate to anything I am doing.  I am not passing any values from the User record to my related record.  I am simply updating a checkbox on that related record.  

Is there some salesforce limitation when dealing with the User object?