Motion Tile & RepeTile problem with black borders

A little followup to this. Yes, I needed to have the Transform effect, and it had to be below RepeTile. For various reasons I couldn't precomp stuff. So I added a second instance of Repetile, and then another instance of Transform (scale) to correct for some weirdness. So the effect tree from the top down was RepeTile-> Transform-> Repetile-> Transform. Kludgy, but worked for what I needed it to do.

If you need the transfer effect, you should just move your motion tiles effect above the transfer effect. it will work.

Roland is right, it could be because of the Transform effect. What happens if you turn that off?

A workaround could be to Precompose the Transform effect and Brightness and Contrast with the layer. Then apply the Motion Tile effect to the resulting comp. To overcome the annoyance of having the Transform effect controls within the nested comp, add the Rotation property to the Essential Graphics panel (plus any other effect properties that you may want to control in the main comp). When you open the nested comp in the main comp, you should now be able to access the Transform effect controls in the Master Properties section of the Nested comp.