Leak...what to do?

[Red Baron]

My transmission has developed a leak from here all of a sudden...

Here is a view from the bottom

Why would it do that all of a sudden? What's the fix for it?

 

[sideSHO]

Thats the fill hole for the MTX.
I would take the plug out and wrap some teflon tape around the threads.
Also a good time to suck the old fluid out and put in some new synthetic.