Los Angeles attorney Gerald Kroll, who is representing injured stunt actors in six cases, has called for licensing and certification for all stunt and special-effects coordinators, it was reported Monday. The call was made last week at a public hearing held by the California Film Commission on unresolved problems in the entertainment industry. Other major complaints focused on problems of filming in Los Angeles. Among them: harassment by city officials, exorbitant costs and excessive fire safety monitoring. More hearings on the matter will be held in October by the State Assembly's subcommittee on arts and athletics.