When I run a particular flow in our Partial Sandbox (Lightning), I get the following errors:

• FIELD_FILTER_VALIDATION_EXCEPTION: Value does not exist or does not match filter criteria.
• UNABLE_TO_LOCK_ROW: unable to obtain exclusive access to this record or 165 records. 
• CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY: SVT_OpportunityTrigger: System.LimitException: Too many SOQL queries: 101.

I think the first one is a matter of checking related lookup filters on applicable fields in the objects utilized in the flow. The second one I don't know what it means. The third one is something wrong with my Trigger (set up by a consultant), but I don't know Apex all that well.

Can someone help with one or all of these error issues? Here's the Apex Trigger code for the third error:
 

trigger SVT_OpportunityTrigger on Opportunity (before insert, before update, before delete, 
                                after insert,after update, after delete, after undelete) {
    //System.debug('Before Trigger Control------> ');
    TriggerSettings__c control = TriggerSettings__c.getOrgDefaults();
    if(!control.OpportunityTrigger__c)
    {

        SVT_OpportunityTriggerHandler handler = new SVT_OpportunityTriggerHandler(Trigger.isExecuting, Trigger.size);
        SVT_OpportunityHandler opportunityHandler = new SVT_OpportunityHandler();
        /*
        SVT_OpportunityTriggerHandler.hasBeenCalled = true;
        
        if((Trigger.isBefore&& Trigger.isUpdate)||(Trigger.isAfter && Trigger.isInsert)||(Trigger.isAfter && Trigger.isUpdate)){
            OpportunityHandler.newSObjectMap = Trigger.newMap;
            OpportunityHandler.SObjectIds = Trigger.newMap.keySet();
        }
        
        if(Trigger.isUpdate || Trigger.isDelete){
            OpportunityHandler.oldSObjectMap = Trigger.oldMap;
            OpportunityHandler.oldSObjects = Trigger.old;
        }
        
        if(Trigger.isInsert || Trigger.isUpdate){
            OpportunityHandler.newSObjects = Trigger.new;
        } */
        
        handler.handler = opportunityHandler;
        
        if(Trigger.isInsert && Trigger.isBefore){
        //  System.debug('Trigger Before Insert Check');
            handler.onBeforeInsert(Trigger.new);
        }else if (Trigger.isInsert && Trigger.isAfter){
            //System.debug('Trigger After Insert Check');
            //try{
            handler.onAfterInsert(Trigger.new, Trigger.newMap, Trigger.newMap.keySet());
            If(!System.isBatch()) SVT_OpportunityTriggerHandler.onAfterInsertAsync(Trigger.newMap.keySet());
          //  OpportunityLineItemTriggerHandler.onAfterInsertAsync(Trigger.newMap.keySet());
            //}catch(Exception ex){
                //System.debug('Error: '+ ex.getMessage()+'. ON LIne: '+ ex.getLineNumber()+'. Stack Trace: '+ ex.getStackTraceString());
        //  }
        }else if (Trigger.isUpdate && Trigger.isAfter){
            //System.debug('Trigger After Update Check');
            handler.onAfterUpdate(Trigger.new, Trigger.old, Trigger.newMap, Trigger.oldMap,Trigger.newMap.keySet());
           // OpportunityLineItemTriggerHandler.onAfterUpdateAsync(Trigger.newMap.keySet());
        }else if (Trigger.isBefore && Trigger.isUpdate){
            //System.debug('Before Update Trigger Check');
            handler.onBeforeUpdate(Trigger.new, Trigger.old, Trigger.newMap,Trigger.oldMap, Trigger.newMap.keySet());
        }else if (Trigger.isBefore && Trigger.isDelete){
            //System.debug('Before Delete Trigger Check');
            handler.onBeforeDelete(Trigger.old, Trigger.oldMap);
        }else if (Trigger.isAfter && Trigger.isDelete){
            //System.debug('After Delete Trigger Check');
            handler.onAfterDelete(Trigger.old, Trigger.oldMap);
        }else if (Trigger.isUndelete){
            //System.debug('Undelete Trigger Check');
            handler.onUndelete(Trigger.new);
        }
        //added by Aman    -- COmmented out by PR 12/19/2017. This is purely for launch. Remove this ASAP.
  /*     if((trigger.isafter && trigger.isinsert) || (trigger.isafter && trigger.isupdate)){
         try{
            SVT_OpportunityHandler.CreateContactFromOpp(trigger.new,trigger.newmap,Trigger.newMap.keySet());
            }catch(Exception ex){
                System.debug('Error: '+ ex.getMessage() +'. Stack Trace: '+ex.getStackTraceString());
            }
            
        }  */
    }
}