403 Forbidden with POST to Mendix Application

We use 8.6.9 but somehow this version is not in the Drop-down list? A few months ago we got recommended to update from 8.6.4 to 8.6.9 by our Mendix contact. Anyway: We have the functionality that we send documents to our Mendix Application using REST POST / Username and Password and have one RESTuser for this. These documents are being processed depending on dynamic information in the name etc. This worked for over a year. Now I have the problem that the API returns 403 Credentials valid, but not authorized. So endpoint and credentials of the Application are correct. I want to emphasize that current settings have functioned, but stopped functioning either since the update to 8.6.9 or another unknown change.     I checked Security, but as far as I can assess, this is correct. I found the following: But this Boolean is Default False in our Application. Honestly, atm I have no idea how to move forward. All the information I can find are about triggering API from within the Application, but this functionality is to the Mendix Application. And I can't rime the behaviour with the logs. (I have Logging in the FileUpload Microflow, but because of the 403, this MicroFlow is never triggered.) Thanks for the support in advance :)
3 answers

Hi Arie, 
does the user that uses the REST function have the userrole 'RestUser'? If you can't come in the REST-microflow that means you are blocked by Mendix (unauthorized: 403) before reaching to the actual microflow.
Also, it can help us help you, if you post the error which you get.


Hi Martijn,

(It seems you have to right-click the images and open in new tab to see the full image. My bad.)

Yes, the Role is correct:

This is also the Role assigned to the MicroFlow.
Here Mendix describes the response as Valid but not Authorized, so I am inclined to look in the Application I guess?

Below the error we get:


Is this what you are looking for? 

(It seems you have to right-click the original images and open in new tab to see the full image. My bad.)