UModeler 2.6.14 has been released for hotfixes. Here are the release note.
Hotfix : Fixed a bug where some error messages are thrown when an empty UModeler object exists in a level. The error message says about UV generation.
Hotfix : Fixed a bug where each polygons has its own UV rotation/scale pivot point. Now the UV center of the selected polygons is a pivot location.
Refactoring : UModeler.active is replaced with UMContext.activeModeler