You will need to add /rest in between, so for instance, “https://localhost:8080/rest/ApiName”
I just tried to do it that way, I tried: https://localhost:44364/rest/Administration/GetAssets and https://localhost:44364/Administration/rest/GetAssets
But it’s still giving me the same error 560:
Do you have an error message in your Studio Pro console when you try to access the REST service from a browser?
Can you try to delete the actionButton3 on your form and replace it with a new action Button?
I had this issue two times in my last projects and couldn’t figure out what the ‘generic’ error description is about. Replacing the existing button with a new button helped somehow. Let me know if it helped in your case too :)
Otherwise: Did you already try to access the local API via Postman first so you can be sure that the issue is Mendix related?
Terry Fey, probably need to add the certificate as known. You can follow the instructions in the link
Another solution: Add you cetificates: