Yesterday, I started to get this error on my Android phone. I have the latest Field Maps and Collector app and my Android is fully updated. Not sure why I got this error today, after never receiving it... I have attached the screenshot from my phone.
We have the same issue on android. Downloading the certificate from a browser and exporting/importing to android failed, since newer android versions ask for a private key which we do not have. How do we deal with this issue?