Animation playback using property - bug?

This started out with me asking how to fix this issue, but I think I’ve found the source of a bug instead, but maybe somebody can enlighten me as to what the issue is.

So with a small game project I’m working on, I’ve found that by changing anything to do with the scene’s “Sun” light object, it will break animations that rely on a property. My question is, why? I haven’t been able to reproduce the error with any other blend files but it would be nice to have some support to help me figure out why this is.

If needed I will post the file that I’m having issues with.

I have no idea what you are talking about.

I thought it might be a bit hard to tell, here’s what I’m talking about.

If you change the sun’s settings for example turning off shadows, property based animations will break.

I’m using 2.77 btw

I can’t find any problem.
There’s a bit of very fast shake going on with the animations, where position is getting set strangely for just one frame.
I don’t know what’s causing it, but it could be anything. It’s present from the first time I open the blend though, and isn’t affected by the sun.

You’ve got a lot of different objects, lots of ray casting objects, 3 sets of armatures and meshes, it’s rather difficult to keep track of everything.

Another area that could cause problems is with the kind of properties you’re using. If you intend a property to be an int (1,2,3 etc…) you should set it like that from the start. Likewise with floats (0.02,2.5,4.9999 etc…) otherwise you can get small errors when python gets confused about what kind of number it is dealing with.

i have this same issue on Blender 2.77, dont know what cause it though

to solve this i simply use 2.75 and it works there.