@Austen Brown and I both happened to be building adaptive cards to add to our NXT environments and could not get the card to display.
After some digging around, we noticed that the HTTP POST URL created from the HTTP action, even when encoded, was much shorter than others that were working. The only way to fix this issue was to change the “Who can trigger the flow?” from Any user in my tenant to Anyone and the link became longer and when encoded and added to the app URL all worked great?
We were both using the PA template that Blackbaud has published for creating an adaptive card so wondered if this was a bug or if the template had changed since we last used it?
@Erik Leaver @Heather McLean @Glen Hutson @Ashley Moose