@blakeyrat said:
If VS is parallelizing compilation, the error could (potentially) depend in somewhat non-deterministic factors. Maybe? I dunno, just guessing.
Most likely it's just running out of memory (or more correctly, address space). Quitting and reoping it works, but Clean All/Rebuild All doesn't.
Usually manifests itself as a "Not enough storage is available to complete this operation," but sometimes it just goes for random.
(Code is a 3 form access database frontend that has grown to 200 forms, 400 tables etc).