When I try to go to ruleset in data cloud, and click New button, I receive several errors including
An internal server error has occurred Error ID: 1065883952-6153 (1010177878)
Also I can't select a data space from the dropdown list.
It is related to invalid data spaces.
We need to delete invalid data spaces or open a SF Support case.
Update from SF Support.
Since there is no UI for Data Space deletion, one has to use Workbench or other API tool to query Data Space records using the SOQL query
SELECT Id, Name, Description, DataSpaceApiName FROM DataSpace
then follow the links for the broken data space records and delete them using workbench.