When you have a macro the standard cell grid (

ROWS

in the

DEF

) will get cut where ever they are (and a bit around, specified by the halo). However the global placement doesn't seem to pay much alignement to the grid, it avoids the macro "mostly" but some cells get still placed overlapping and it counts on detailled placement to legalize. Problem is detailled placement will only move cells withing some fixed radius AFAIU and so if it got placed too far aways from any legal location, you get a

detailed placement failed for XXXX

error.