I need a second set of eyes on this trigger I'm trying to build.  I don't have a lot of experience with triggers so I found one I'm trying to modify to my purposes.

On our opportunity object, if a user needs to make changes after it's been sold, they have to clone the record and start over, instead of editing.  I have a checkbox field called Superceded that should be checked on the original opportunity after it's cloned (this is what I'm trying to accomplish with my trigger).

I also have a lookup field for the newly clonsed record that will show the parent or original opportunity called Previous_Version__c.

I'm trying to create a trigger that will fire after insert on new opportunities only if the Previous_Version__c field is populated.  The trigger should update the opportunity in the Previous_Version__c lookup field and check the Superceded__c checbox on that parent record.

Here is what I've got so far:

trigger UpdatePreviousOpp on Opportunity (after insert){
 
Opportunity[] opp;
opp = Trigger.new;
 
set<Id> prevoppIds = new Set <ID>();
 
for (Opportunity op : opp) {
      if(opp.previous_version__c != null) {
         prevoppIds.add(op.previous_version__c);
    }
 
Map<ID, Opportunity> proppsToUpdate = new Map<ID, Opportunity> (
    [select Id, supercedure__c from Opportunity
    where Id in :prevoppIds]);

 
List<Opportunity> preoppUpd = new List<Opportunity>{};
 
for (Opportunity opp : preoppsToUpdate.values()) {
    opp.supercedure__c = true;
    update opp;
    preoppUpd.add(opp);
}

if (preoppUpd != null && !preoppUpd.isEmpty())
Database.update(preoppUpd);

}
}

Here is the message I'm getting.  Any idea how I can get this to work?