API: "Malformed App ID"

Hello everyone:

I am in the middle of simple API call to save the record’s knack ID. During my call, the console states I am having a 400 error: Malformed App ID. I am using Knack.application_id for my app ID; however, I have used our actual knack app ID as well. I switched to the Knack.applicatoin_id function to try to workaround this issue with no luck.

headers: {
‘X-Knack-Application-Id’: Knack.application_id,
“X-Knack-REST-API-Key”: ‘knack’,
‘Authorization’: Knack.getUserToken(),
‘Content-Type’: ‘application/json’ }

Looks right and in the console Knack.application_id comes up.
Maybe try without the Content-Type header as an idea - we have an app that works without it.