What does "Only one modifiable entity is allowed" in the Boolean tool mean?(parts studio in context)

sam_anderson699

Hello, I am making something for fun and I want to combine all of these parts together, but I am unable to. It is the assembly named "Landing Platform" don't pay attention to the rest. Create a part studio in context and try an Boolean all of the parts. Thats what im dealing with. It tells me "Only one modifiable entity is allowed" when I try to union them. If you know how to solve this, of know how to get all of these parts as one, it would be greatly appreciated! 
Document: https://cad.onshape.com/documents/6b40c41e158573655fd2e32d/w/f2fe592cdcb4480ddd15a1bc/e/1a248ef216f67294f3862e2e
If you have any troubles editing let me know!

glen_dewsbury

Try Simplify FS to combine. Copy this link and paste in search for add features.
https://cad.onshape.com/documents/3f84343841cb6d7fead072c8/w/e8588a72f5052afeb63e853d/e/e6b43bb1112db2e0f9f965b0

Here is a sample from your document. https://cad.onshape.com/documents/911b65a2ea55f24e195891ff/w/96c7e63588a8151b9b051e67/e/4945bae28f273904858fc669

glen_dewsbury

Try Simplify FS to combine. Copy this link and paste in search for add features.
https://cad.onshape.com/documents/3f84343841cb6d7fead072c8/w/e8588a72f5052afeb63e853d/e/e6b43bb1112db2e0f9f965b0

Here is a sample from your document. https://cad.onshape.com/documents/911b65a2ea55f24e195891ff/w/96c7e63588a8151b9b051e67/e/4945bae28f273904858fc669

sam_anderson699

glen_dewsbury said:

Try Simplify FS to combine. Copy this link and paste in search for add features.
https://cad.onshape.com/documents/3f84343841cb6d7fead072c8/w/e8588a72f5052afeb63e853d/e/e6b43bb1112db2e0f9f965b0

Here is a sample from your document. https://cad.onshape.com/documents/911b65a2ea55f24e195891ff/w/96c7e63588a8151b9b051e67/e/4945bae28f273904858fc669

THANK YOU SO MUCH!!!

(i forgot I made this post)