Saving a process errors because of missing ApplicationPoolPassword

Upgraded from 3.2.19 to 3.3.10 and now while trying to save a process step, the following error occurs. The step has: IIS Web Site, IIS Application Pool, IIS Bindings and IIS Authentication features, but the identity for the app pool is set to simply application pool and the website doesn’t even mention any possibility of changing the app pool password.

octopus.min.js:19 TypeError: Cannot set property ‘Octopus.Action.IISWebSite.ApplicationPoolPassword’ of undefined
at Object.preSave (
at Array.forEach (native)
at Scope.$ (
at fn (eval at (, :4:203)
at callback (
at Scope.$eval (
at Scope.$apply (
at HTMLFormElement. (
at HTMLFormElement.jQuery.event.dispatch (

Never mind, somehow my browser was still running a cached version of the javascript.