Sharing the converter I made for my working to "downgrade" from version 11 to ver 8.
Be careful of the losses that occur in this downgrade and review the warnings. In particular the loss of 2 of the 6 restraints which can be defined in one auxiliary filed in ver 11 whereas only 4 can be defined in ver 8
Ver 11 to ver 8 Converter

Regards,

Tanveer