Please review the following thread that has been marked a solution regarding "register error with flow".
If this does not solve your problem, please reply back in this thread.
The thread that you have linked to does not have a solution at all for the issue that people have raised in this thread. The solution was to not use a Flow at all. The issue we have had is that sometimes the Flow just won't register to a Powerapp. When this happens, you have no idea why, and don't know how to start resolving it. Microsoft needs to help people understand what causes this issue, not see how people solved their particular problem by doing something different.
PowerApps is a great product, but when something doesn't work it can be a very frustrating experience to try to debug it.
It would be much more useful if you could explain what the causes are getting this error. I can't even remember what my specific issue was because I think I just had to do it a different way because I could not get the Flow to register and I had no information about why. Surely Microsoft has some idea of what causes this issue?
Unfortunately your suggestion doesn't work -
Create new from Flow
Export and then import, update existing flow
Export and then import, create new flow
Create new flow from powerapps
Nothing works, always get the same generic regsitering error.
I have ahd this problem and the only way to fix it was to get the creator of the flow (who needs co-author access) to peform the operation.
THis worked for me. Nothing else did even if I was a co-author of the flow.
I'm glad that worked for you. I am the creator.
However, for what its worth, I realised the auto generated JSON schema (I was using response-request action) was missing some data types for some coloumns. Once I filled those in it registered happily.
Been chasing this bug for good 3-4 hours
TLDR - yes it is.
In my case the auto-generated schema was the culprit and fixed quite easy. However, figuring out THAT was the issue took hours.
Providing a more useful/specific error message would go a long way, rather than a generic "failed to regsiter service".
... or hardening the auto create schema function.
Thx for following up.