We've released another hotfix for some additional stability problems and gameplay issues players have encountered in Milestone 5. Please do report any bugs you encounter on the bug reporting subforums and we'll do our best to look into them.
Bugfixes:
Fixed a rare crash that could occur if a squadron intercepted a UFO at the exact moment it despawned.
Fixed significant slowdown occurring when a unit crushed something while moving (most obvious when moving through fields of hay).