Do you have any idea why it works when we test on Companies in ISV Boardeaser AB but not for our customers? When I go through the same flow as a customer: 1. Sign in to Boardeaser 2. Click on our generated authorize link ( https://connect.visma.com/connect/authorize?client_id=isv_boardeaser&redirect_uri=https%3A%2F%2Fapp.boardeaser.com%2Fintegrations%2Fvisma_net&response_type=code&scope=vismanet_erp_interactive_api%3Aread&state=state) 3. I sign in to Visma.net 4. I select `Visualby Test Company` 5. It redirects to Boardeaser 6. We request a token ( https://connect.visma.com/connect/token) 7. The account is connected. But for our customer it fails on step 6 and we get `invalid_request` as the error message with status 400. The API call for step 6 is as follows: POST https://connect.visma.com/connect/token code=valid_code&grant_type=authorization_code&redirect_uri=https%3A%2F%2Fapp.boardeaser.com%2Fintegrations%2Fvisma_net&client_id=isv_boardeaser&client_secret=fake_secret headers: {"Accept"=>"*/*", "User-Agent"=>"rest-client/2.1.0 (darwin23 arm64) ruby/3.3.1p55", "Content-Type"=>"application/x-www-form-urlencoded", "Content-Length"=>"150", "Accept-Encoding"=>"gzip;q=1.0,deflate;q=0.6,identity;q=0.3", "Host"=>"connect.visma.com" response status: 400 body: {"error":"invalid_request"} ... View more

We have now validated that the customer has API-user rights. We tried removing the rights from one of our test users and get a access denied message in the authentication process when that is the case.  The customer can go through the whole authentication process and pick the correct company but still gets a 400 response with {"error":"invalid_request"} in the token request. ... View more

After making the changes you suggested, we still get the same error when trying to get a token for the customer. It still works perfectly fine when we try with our own test users. ... View more