porting SOPC builder from 8.1 to 11.0

Hi

when I open a system created by version 8.1 in version 11.0 I get the following error message on some of my user created instances:

Error: my_name: Setting TOP_LEVEL_HDL_MODULE is not allowed when instantiate_in_system_module = false

can anyone shed some light on this message for me?

thanks