Hello and welcome.
-Which model Mac?
-Do you have a Time Machine or other backup of your data?
When you get to that step, it usually means to install is complete and the Mac has started up and is letting you know what software is incompatible and has been disabled. If you have tried unplugging/plugging in both several times, then you may simply have to hold the power button until the Mac powers off. Then, power the Mac back on and see if it rappers and lets you click Continue, or if it simply skip it and starts up normally. It may take a while to startup due to the forced shut down.
C