For me it was the same as @grant.reid and @sumya ā go into the Home Assistant configuration folder and check that the tesla_fleet.key matches the original private key that was generated. If it does not, update the key in the configuration folder and then reload the Tesla Fleet integration. Everything worked after that.
Had the same issue. Using MyTeslaMate App.
My problem was solved by: renaming key from tesla-fleet.key to tesla_fleet.key.
The integration does this by itself, but didnt fix the issue, even by deleting the wrong named key and reloading integration. By uploading the renamed key, without having the integration renaming it, it fixed everything!
Thanks for the hints and tips here, I was able to get the first error solved.
However, Iām still facing the following one:
'Session' object has no attribute 'epoch'
any idea how to get it fixed? Iām running 2025.3.2