@Mks123 We take this issue very seriously, does this issue still exist now? If yes, can you upload a photo about this issue? 

Before you upgrade the firmware, what's the version of your firmware? Do you bind your TP-Link ID to your OC200? Do you connect your OC200 to the Internet? 

If the problem still exists, please tell us. 

@forrest Thanks for the fast feedback. I updated everything manually to the most recent firmware. After a couple of minutes the "check for upgrade" works. No idea why.

I've not linked my devices to an TP-Link ID.

Thanks

@Mks123 It may be related to the network stability. If this issue occurs again, please check if the OC200 connect to the Internet normally.