Apex trigger AcountTriger caused an unexpected exception, contact your administrator: AcountTriger: execution of AfterInsert caused by: System.UnexpectedException: Salesforce System Error: 1301043935-22543 (1350809315) (1350809315): Trigger.AcountTriger: line 8, column 1

trigger AcountTriger on Account (after insert,after update) {
    Map<String, Object> params = new Map<String, Object>();
    for(Account acc : Trigger.new){
        params.put('accountEmail',acc);
        Flow.Interview.test testflow = new Flow.Interview.test(params);
        testflow.start();
        String localOutputParameter = (String)testflow.getVariableValue('accountEmail');
    }
}