Shell extensions which are blocked by default has information on what's blocked by default and how to unblock extensions (whether they are blocked by default or were blocked by Opus automatically after it detected a problem).
From your screenshots, it looks like there are programs in the Opus menu which aren't in the Explorer menu as well as vice versa. (The Split and MD5 Checksum items, unless they are part of Opus, but the large, cut-in-half icons suggest they're not from Opus and coming from something that does custom-drawn menu items in a non-standard way.)
That makes me wonder if you are are running 32-bit Opus from a USB stick on 64-bit Windows or anything like that?