Maybe you need a new, sharper needle to sew that dense of a project

I also put in a new needle. (I'm using sharp Titanium).
That didn't help either. My machine is fairly new, but I'm wondering if it is my machine.

Could be stabilizer too. It may just be the design itself. Is it purchased or a free download. I have problems on some of the freebies & I get antsy on the thick stuff because of the noise it makes.

The software is purchased from Embroidery Haven. Beautiful design and I have purchased from them before. The stablizer is Badgmaster. I use Madiera poly thread which has done well for me. However, on this heavy design the bobbin thread occasionally piles up and causes a huge thick lump for no apparent reason. I'm doing freestanding lace and have done a lot of it but not this heavy a design.

Appreciate your comments.

My machine's tension is usually too loose when my machine does the "bird's nest" thing.

I tried lace once & it didn't do well. I had some bird's nests & it finally pulled a big hole in my stabilizer & I haven't tried again.