Can't select employee's to work on game

Sometimes (usually whenever I have someone researching or on vacation) when I try to make a game I can’t drag any of my employees to work on specific engines - the entire left field is gone, so I don’t get any modifiers and my game comes out as total crap.

you didn’t make you game a medium or large sized game then, because you can set people who are on vacations to work on things, but they just won’t.

It doesn’t let me set any of my employees - even the ones not on vacation or working on other projects. This happens on both small and medium games (I stopped playing after it happened the fifth time so I haven’t tried large games) ALL my workers do not show up on the left when it comes time to select whose working on what feature. I can only click next, which results in a game generated without the character modifiers.

Are you sure? You can’t employ employees to work on specific things on small games only, and ONLY.
You probably didn’t click the right thing!