All Platform pieces are cut and drilled by a computer, so while possible, it's unlikely that any of them are drilled/cut incorrectly. Oftentimes we find that when pieces are not sitting correctly and there are gaps between them it's a matter of installation not being completely sound in the earlier stages of assembly.
This may cause pieces later in the assembly to sit incorrectly (e.g. the main desktop not sitting flush on the two internal legs or the top hutch not sitting flush on the two vertical dividers on the main desktop).
We recommend backtracking a few steps by disassembling some pieces and loosening some “B” screws around the structure where needed in order to allow some play. For example, taking off the top hutch and loosening the “B” screws that go through the two outer legs into the side of the main desktop. When this is done, Platform will become more flexible and things should then start to fall into place a bit better.
If you still need help after trying these things, please submit a ticket with some photos clearly showing the issues and we'll be happy to assist further.