Tomcat ...
Thanks for that. I've reverted to 4.51, Stable for now; if this behaviour is due to the use of dev3, which is what is implied here, it's a bug that needs fixing, as it's inconceivable to go through all the Meshes that need attention. I'll swap over to dev3 to confirm that it does, indeed, 'fix' the issue, but it would make dev3 unusable for me until a fix in dev4 or such. Back shortly...
Edit : I can confirm that assigning the appropriate Skeleton, either by choosing from a list (a bit long to refresh...) or by 'dragging' the Skeleton to the Assign box, does fix the issue. Does this need 'Reporting', and, if so, by whom, and how..?