Just in case you have fallen victim of the confusion I see often in online communities, blogs, but also Microsoft official documentation: Dynamics 365 Business Central sandbox is not the same as Dynamics 365 Business Central preview. They are two different things. Keep in mind, in this blog post I am not talking about sandbox container environments (on-prem); I am only talking about online sandbox environments.
This is not pure semantics. Things in sandbox environments (and I mean, real sandbox environments of Business Central) differ from things in preview environments.
In just under two weeks I’ll have to present how to use OAuth 2.0 authentication to call REST APIs of Dynamics 365 Business Central. Should be easy. Not only I have already done OAuth integrations, but there is also a nice step-by-step tutorial by Microsoft specifically done for Business Central. So, I followed the steps to the letter (as much as that was possible), and after all was done, I tried to use Postman to get myself an OAuth 2.0 token for invoking Business Central REST APIs, but it didn’t work. No matter what I did, Postman kept returning this:
(Could not complete OAuth 2.0 login. Check Postman Console for more details.)
So I checked the Postman Console for more details.
Quite some detail.
After a ridiculous amount of time troubleshooting this, I figured it out. Depending on how your Business Central trial account was configured you may encounter this problem. On top of it add the fact that the documentation isn’t exactly straightforward and at couple of places leaves you (educated-)guessing. So I decided to write this blog in case you (or myself at some future point after I will have forgotten I’ve been in this mess) ever need it.