MEP 2015 is a 64 bit program, previous versions were 32 bit and the extras will not work with MEP 2015.
You will have to update the extras to 64 bit versions if they are available.
A member on the forum is trying to do the same and has found a 'bridging' program which 'allows' 32 bit addins to run on 64 bit software, however there has been no feedback from them whether it works or not.
Hey erik62, I'm using Video Pro X6 with is also 64bit, like the new MEP 2015. Like you I discovered that my NewBlueFX plug-ins were not compatible...but I'm happy to report that a support staffer at NewBlueFX has indicated that they are coming out with 64-bit versions of their plug-ins (he referred to them as "consumer versions"). And he gave me access to some of the pre-release programs, which I installed and am happy to report show up in both Video Pro X5 and X6 and work properly.
When installing these new versions you see "Magix" and "Magix-64 bit" as options...and I didn't have to activate them, they installed over the older version and were immediately available in both X5 and X6. So I'm guessing this will work for MEP 2015 as well...
I purchased Titler Pro 2, which works within X5, and I see the "LE" version is offered in MEP2015, so I'm hopeful that that will become compatible with X6 also...but its a good lesson...alliances that form between vendors and Magix are not guaranteed to carry over between versions...so purchase plug-ins at your own risk...
No announcements on the NewBlueFX site yet...but I hope they do so soon...as I'm still using X5 for most of my editing, and I'd like to make the switch totally to X6...