I'm getting an error message when I try to save records. The error message is:

     URL No Longer Exists
You have attempted to reach a URL that no longer exists on salesforce.com. 

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• A bookmark to a particular page, such as a report or view 
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The Visualforce page:

  <apex:page controller="sampleitem">
  <apex:form >
      <apex:pageblock >
          <apex:pageblocksection >
              <apex:pageblocktable value="{!lstWS}" var="S">
                  <apex:column headerValue="Select">
                      <apex:inputcheckbox value="{!S.ischecked}"/>
                  </apex:column>
                  <apex:column headerValue="Name">
                      <apex:outputtext value="{!S.swi.Name}"></apex:outputtext>
                  </apex:column>
                   <apex:column headerValue="Stage">
                      <apex:outputtext value="{!S.swi.Stage__r.Name}"></apex:outputtext>
                  </apex:column>
                  <apex:column headerValue="Item Name">
                      <apex:outputtext value="{!S.swi.Item__r.name}"></apex:outputtext>
                  </apex:column>
              </apex:pageblocktable>
          </apex:pageblocksection>
          <apex:commandButton value="Select" Action="{!doSave}"/>
      </apex:pageblock>
  </apex:form>

The class:

    public with sharing class sampleitem {

public PageReference doSave() {
    List<sample_Item__c> lstswi = new List<sample_Item__c>();
    List<Project_Task__c> lstpwi = new List<Project_Task__c>();
    for(wrapperSample objws : lstWS){
        if(objws.ischecked == true){
            Project_Task__c objP = new Project_Task__c();
            if(pid != null)
            objP.project__c = pid;
            objP.End_Date__c = system.today();
            objP.Start_Date__c = system.today();
            //objp.Predecessor_Task__c = objws.swi.Predecessor_Task__r.Id;
            if(objws.swi.predecessor_Task__r.Name != null)
            objP.Name = objws.swi.predecessor_Task__r.Name;
            objP.Owner__c = Userinfo.getUserId();
            if(objws.swi.project_stage__r.id != null)
            objP.Project_Stage__c = objws.swi.Project_Stage__r.id;
            if(objws.swi.Type__c != null)
            objP.Type__c = objws.swi.Type__c;
            objP.Task_Status__c = 'In Progress'; 
            lstpwi.add(objP);
        }
        }
    insert lstpwi; 
    return (new pagereference('/'+pid).setredirect(true));
}

public String pId = apexpages.currentpage().getparameters().get('pid');
public String wtId = apexpages.currentpage().getparameters().get('wid');
public List<sample_Item__c> lstSWI{get;set;}
public wrapperSample objWS{get;set;}
public List<wrapperSample> lstWS{get;set;}
public sampleitem(){
    lstSWI = new List<sample_Item__c>();
    lstSWI = new List<sample_Item__c>();
    lstSWI = [select id,name,Stage__r.Name,Item__r.name from sample_Item__c where Template__c =: wtId];
    lstWS = new List<wrapperSample>();
    for(sample_Item__c objSWI : lstSWI){
        objWS = new wrapperSample();
        objWS.swi = objSWI;
        lstWS.add(objWS);
    }
}

Attribution to: rakesh

Possible Suggestion/Solution #1

It sounds like you're trying to save a record with an empty required field. Double-check which fields are required for the object and verify they are populated.

Update

Based on your comments below, your URL is Sampleitems?+pId=a0FW00000009RqX&WId=a0DW0000000I1bzMAC. Note that you have an extra plus sign (+) between the question mark and the paramenter pId.

Attribution to: Mike Chale

Possible Suggestion/Solution #2

I see that you've checked

if(pid != null)
          objP.project__c = pid;

This would potentially mean that if pid is null, objp.project__c has a null value.

This would cause an error when the records are inserted at

insert lstpwi; 

You probably want to assign a default value to cater for cases where pid comes out to be null. Are you passing a ?pid=value in the URL so that it is available as a query parameter to set on Project ?

Attribution to: techtrekker
This content is remixed from stackoverflow or stackexchange. Please visit https://salesforce.stackexchange.com/questions/4645