Addressed this as a permission-state mismatch.
The checkbox uses the lot’s BuildRoommates set, while authorization previously trusted only the avatar’s cached permission level. If those diverged, the box could appear unchecked while construction remained enabled.
Changes:
Full build access now requires membership in BuildRoommates and the corresponding permission level in VMDefaultValidator.cs (line 22).
Expanded catalog access uses the same authoritative check.
Community-lot benefactors follow the same rule in VMFSOCommunityValidator.cs (line 63).
Environment changes are protected by that validation in VMNetChangeEnvironmentCmd.cs (line 25).
The client’s Build Mode button now reflects the authoritative result in UIUCP.cs (line 420).
Ordinary roommates retain the intentionally limited catalog permissions already present in the game, but cannot use construction tools or the expanded builder catalog unless checked.