Inconsistent Islands Error Handling
For some packer operations the user may specify parameters on a per-island basis (e.g. group number, per-island rotation step, lock group number etc.). The problem is that Blender does not internally maintain information about UV islands. That is why the user needs to specify aforementioned parameters on a per-UV face basis in the Blender UI. During the operation, the packer uses those per-face values to determine values assigned to UV islands.
The Inconsistent Islands error is returned by the packer every time the user assigns different parameter values to two faces belonging to a single UV island – in such a situation the packer cannot determine the parameter value for the island itself in the unambiguous way. After returning an error, the packer will also select all problematic islands, so that parameter assignment may be easily fixed by the user.
In order to fix this error, the user has to select every problematic island one by one, and assign a single parameter value to all faces in every island.
For example, if the packer returns an error such as the one in the picture above, it means that at least two faces of the given set of islands have a different Rotation Step values assigned.
Handling of an exemplary Inconsistent Islands error was presented in the Groups To Tiles tutorial: