Sorry that's my only idea short of a factory reset.
I have had my S6 for a few months without any problems at all, and never needed to take the SIM out or power down the phone.
Now I need to change the SIM and on restart it is asking for a PIN code, not a sim code, but a device pin code.
"Enter PIN instead of using fingerprint recognition after restarting device to protect fingerprints"
Funnily enough this is a very efficient way of protecting the fingerprints, as I have only ever used Fingerprint scanning, and the backup passcode - never a PIN so i can no longer access the device.
I don't have Findmyphone so cant open it online, Android device manager will only lock the phone and cannot unlock it.
What can i do to get access to my phone (without a hard reset and losing all my data and files on the phone)