SOLVED: some of required entries in cron_task_runs were missing.   
	List: 
	process_service_changes for all companies 
	backups_sftp for company 0 
	backups_amazons3 for company 0 
	license_validation for company 0  
	SQL commands. 
	For process_service_changes. Note (use your own company ids): 
	 
 
INSERT INTO `blesta`.`cron_task_runs` (`id`, `task_id`, `company_id`, `time`, `interval`, `enabled`, `date_enabled`) VALUES (NULL, '29', '2', NULL, '5', '1', NOW()); 
INSERT INTO `blesta`.`cron_task_runs` (`id`, `task_id`, `company_id`, `time`, `interval`, `enabled`, `date_enabled`) VALUES (NULL, '29', '3', NULL, '5', '1', NOW());
	 
 
	For other tasks: 
	 
 
INSERT INTO `blesta`.`cron_task_runs` (`id`, `task_id`, `company_id`, `time`, `interval`, `enabled`, `date_enabled`) VALUES (NULL, '9', '0', NULL, '5', '1', NOW()); 
INSERT INTO `blesta`.`cron_task_runs` (`id`, `task_id`, `company_id`, `time`, `interval`, `enabled`, `date_enabled`) VALUES (NULL, '14', '0', NULL, '5', '1', NOW()); 
INSERT INTO `blesta`.`cron_task_runs` (`id`, `task_id`, `company_id`, `time`, `interval`, `enabled`, `date_enabled`) VALUES (NULL, '17', '0', NULL, '5', '1', NOW());