Editing a dictionary on AEM Forms fails with "Cannot read property 'isCollection' of null at ae (datadictionarycontrol.min.js:269)"

Editing a Dictionary with AEM Forms causes the browser to load the page indefinitely. The Developer Console shows the following error:

• AEM Forms - All versions

This issue most likely occurs with an AMS where the dispatcher is missing some Message Headers. By default, the following Message Headers are allowed on AMS environments:

"CSRF-Token"
"X-Forwarded-Proto"
"Forward"
"referrer"
"user-agent"
"authorization"
"from"
"content-type"
"content-length"
"accept-charset"
"accept-encoding"
"accept-language"
"Access-Control-Request-Method"
"Access-Control-Request-Headers"
"accept"
"host"
"if-match"
"if-none-match"
"if-range"
"if-unmodified-since"
"max-forwards"
"proxy-authorization"
"proxy-connection"
"range"
"cookie"
"cq-action"
"cq-handle"
"handle"
"action"
"cqstats"
"depth"
"translate"
"expires"
"date"
"dav"
"ms-author-via"
"if"
"lock-token"
"x-expected-entity-length"
"destination"

"X-Content-Type-Options"
"Server-Agent"
"X-Forwarded-For"
"Via"
"DNT"
"disableDefaultTyping"
"X-Requested-With"
"AEP-APP-ROOT"
"Origin"