SSL errors when attempting to update one of our apps usually mean the apps’ software updater was unable to communicate with our update server over the Internet for some reason. Unfortunately the error doesn’t tell us why. Perhaps the server was offline on our end, or perhaps there was a problem with the network connection somewhere between your machine and ours.
Generally, re-trying the updater a bit later often results in a successful download. But if it doesn’t there could be security software on your machine that may be preventing our updater from talking to the Internet. (Little Snitch and NetBarrier are examples of applications that can do this.)
If you don’t have any software like that installed on your Mac, what sort of network setup you’re using when the error occurs? Are you using a dialup modem, DSL, or a Cable modem? Are you at work or at home? Is there a firewall or proxy server installed? Does connecting to a different network (even a hotspot?) allow the update to proceed?
If the update won’t proceed, you should be able to manually install the latest version after downloading it from our Downloads page here:
https://www.omnigroup.com/download/
If you first drag the current version to the Trash, you should be able to place the new version into the Applications folder of Finder. And use it from now on. (Doing so won’t touch your data, settings, or license, which are stored in a different location.)