Build error starting my project in 4.5

I get an error when I try to convert my 4.4.x project in 4.5

The following muddles are missing or built with a different engine version:

Would you like to rebuild them now?

When I say yes it fails and asks me to rebuild the manual and it fails and wont open in 4.5.

I started this project in 3.x and was been on until 4.5.

Are you using sources from GitHub?

I am not using the GitHub code its the win install.

I found a Plugin folder called FootIK that I don’t remember adding seems the 3rd person base uses it.

So I did a test and Any Plugin you add to the folder ask’s you to re compile with 4.5

Might be a preview thingy mhhh, I just used the source from GitHub and every thing seams fine. Could you try adding the required preview release files from GitHub? They might be working well for the preview.