Why do I get this error with SOPC Builder: sopc_builder.dispatch_event: ERROR!

Description

There is a known issue with SOPC Builder, where you will see the above error if you try to generate your system after modifying the name of your DDR/DDR2/DDR3 clocks rather than using the default name given by the tool.

The only workaround currently available is not to change the clock names.

This issue will be fixed in a future version of Quartus® II  software.