Hi, to be more precise: I did not use the function on the dev portal web site - because this is simply not working. I am wondering if this was ever tested ... and if, probably on a local environment, which has much differernt performance (response time) than a real world scenario, with access over the Internet. In my case, I wanted to query the server for integration with FHEM, an open source home automation software. There is a module available (written in Perl). This performs the Access Token and Refresh Token management via scripts. I have seen comments in other posts regarding the Access Token topic, where it was mentioned that scripts would help to overcome timing issues. There is a 20 second window between the two steps to generate the token - possible that 1) access via a Web Browser and then 2) using Postman cases some kind of timeout. In my case, I had another very strange result, a message pointing to wrong syntax (which was even more strange). Well, I have a solution - because I used a different technique. The issue on the Dev Portal is still there, which is a more general problem. I'll try to re-open this case, flag it as "new". The Viessmann Devs should review the function and investigate. Regards, Klaus
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