When adding 'submitter' to an input message to limit the users who can accept the next stage 

i.e. 

 stage "Pull to the Test Environment"
        input message: 'Ok to proceed?', submitter: 'TeamX'

When trying to proceed as a user without permissions there is no feed back as to why you cannot. 

Trying to proceed as a user without permission on the overview page produces this error in Chrome Console

prototype.js:1585 POST http://localhost:8080/job/Testing%20gatling/66/wfapi/inputSubmit?inputId=475c6095275992ca689a7842929d7d8e 500 (Server Error)

Trying to proceed on the 'Console Log' page produces this error in Chrome Console

prototype.js:1585 POST http://localhost:8080/job/Testing%20gatling/66/input/475c6095275992ca689a7842929d7d8e/proceedEmpty 400 (Bad Request)

Going thru to 'Paused for input' on the left hand side (only seems to appear when looking at console log) and clicking proceed without permissions does a full page post and does show some more information.

NB: You'll have the same problem (no feedback) even if you do not have a submitter if you are not logged in.