Hi , I'm getting this error message : System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, SetupChangeTechnologyListCheck: execution of AfterInsert caused by System.QueryException: List has no rows for assignment to SObject: : line 8, column 1

I don't understand why it doesn't find account objects, because there are alot of them in SF ?  Where should I start looking for an answer to this? Many thanks already, if you could somehow help me understand this better.

trigger SetupChangeTechnologyListCheck on Setup__c (after insert, after update)
{

    for(Setup__c s : trigger.new)
    {
        
        Account acc = [SELECT Name, Service_Type_List__c FROM Account WHERE RecordType.Name = 'Main Account' AND Name = :s.Main_Account__c];
                
        UpdateMainAccountTechnologyList techList = new UpdateMainAccountTechnologyList();
        techList.UpdateList(acc);
                
    }
}