Small objects collisions problem

Hey there everyone! I saw this question from way back was never answered, and I’m having this exact problem so let me quote him:

"These smaller cubes fire away at incredible speeds when the player walks into them. I don’t know much about the physics engine so I don’t really know whats wrong. I notice that mass values seem incredibly high, but I’m unsure how to change the mass of the character if that’s the problem.

If that isn’t the problem, how do I go about changing the force the character applies when it moves into an object?"

I have his problem except it’s with small coins. I made a custom UCX collision which is just right, I have done it before. I can post a video although this seems pretty well explained.