I'm not sure - if you would like to embed the video, why are you pasting the Link? It will work like the straight URL, it's logical.
For embedding the video, you need to use an embedding approach, copying the Link value Vimeo provides.
Either this BB code:[vimeo=http://vimeo.com/70921986]
either this one:[vimeo500x281=http://vimeo.com/70921986]
- this is only for experienced users wanting to provide the exact size of the video.
Also, Vimeo has an embedding code, located below the Link field. Check the example:
The best solution is to use this code, actually, the code located in between <iframe>...</iframe>
tags (that stuff about <p>...</p> content is not supported in miniBB and mostly appears like a self-advertising option).
As you see, noone of the Vimeo codes refers to https. That's why I'm not sure why miniBB should support what Vimeo doesn't support itself. I believe, https links should be exactly and only used for being referenced as hyperlinks.
I've checked the current Vimeo solution for miniBB on the demo
, and it still appears to work.