I read THIS post at RFO with interest naturally. The thread is about losing dimensions when linked files are updated. A subtle development in the thread is that radial dimension and linear dimensions are affected differently when a link is unloaded. Aaron Maller noticed that, mentioned it (in the thread) and asked someone at Autodesk about it. They looked into it and replied with:Originally Posted by Autodesk Team Here are the details. This is caused by the inconsistency between linear and radial dimension internal design.

For linear dimension, it handles “Unload a linked file" as a special case of dimension references not visible in the current view, while for radial dimension, it handles the unloading as invalid dimension reference, and thus it requires deletion of the radial dimension when unloading.

We will see how we might improve the radial dimension to follow a similar behavior pattern.The emphasis was added by Aaron. Okay, good to know. For now, radial dimensions are at great peril if they are referencing a linked project. Best bet is to avoid dimensioning to linked elements anyway but especially so with radial dimensions.