I have created language support for a custom language. The files written in that language may contain references to Java packages. Creation and handling of those references works fine - including "Go To Declaration" and auto-completion.
As the last missing thing I have created an ElementManipulator for the PsiElement containing the reference. When I now try to rename a package - either in the Project View or directly on the reference, IDEA tells me "Cannot perform operation. Too complex, sorry!"
There is no Exception in the log file and neither is there one on the console. Any hint how to reduce the complexity of this operation would be helpful.