Supporters from several clubs used pyrotechnic devices such as flares and smoke bombs during matches.
The changes are aimed at tackling discriminatory and inappropriate conduct.
Zaragoza’s have now added another layer to the controversy, sharply criticising the refereeing performance.
Rangers claim Celtic are withholding away tickets unless they agree to exclude members of the Union Bears from receiving allocations.
The case stems from Benfica’s match against Real Madrid in February and an investigation into a potential incident of homophobic behaviour.