but makesdna tells you exactly what is wrong and how to fix it, even if you know none of the rules…
7>Align 4 error (32 bit) in struct: TreeFilterElement i (add 1 padding bytes)
Add one padding byte before i
7>Sizeerror 4 in struct: TreeFilterElement (add 3 bytes)
Add 3 padding bytes at the end of the structure.
the only thing confusing is that the 3 at the end, will be 2 once you fix the i alignment, but really… makesdna is doing a pretty good job at holding your hand here