One of our users was getting the following error today with Power Platform.
Irritatingly, Power Platform also gave a red herring error message like this:
The 429 error is a result of throttling. Licensed users can do a maximum of 40k requests per 24 hours after which they start getting throttled. (The limit is smaller for Pay As You Go plans and unlicensed users. And it accumulates across licenses, so one could have a higher limit too). I was able to run a report via the steps in this document and confirm that this particular user was indeed having around 200k requests per 24 hours and.
Only solution is to wait for the throttling period to end. And fix the Flow if there are inefficiencies. It’s also possible to purchase add-ons to increase the limits by 50k requests per hour, per add-on.