Hello Community,
I encountered the following error while working on Manage Chatter Unit ,

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: EJRESRVA
I tried doing using a new Developer Edition but havn't worked but getting the same error.
Please help me out.

Thanks,
Mounika.

Hello Community,
 I'm Working on the Bulk Apex Triggers Trailhead and its throwing me the following error.
Question:
Create an Apex trigger for Opportunity that adds a task to any opportunity set to 'Closed Won'.
To complete this challenge, you need to add a trigger for Opportunity. The trigger will add a task to any opportunity inserted or updated with the stage of 'Closed Won'. The task's subject must be 'Follow Up Test Task'.
The Apex trigger must be called 'ClosedOpportunityTrigger'
With 'ClosedOpportunityTrigger' active, if an opportunity is inserted or updated with a stage of 'Closed Won', it will have a task created with the subject 'Follow Up Test Task'.
To associate the task with the opportunity, fill the 'WhatId' field with the opportunity ID.
This challenge specifically tests 200 records in one operation.
Here is my code:
trigger ClosedOpportunityTrigger on Opportunity (after insert,after update) {
    List<task> tasktoInsert = new List<task>();
    for(Opportunity opp : Trigger.New){
        if(opp.stageName == 'Closed Won'){
        Task t = new task();
        t.subject = 'Follow Up Test Task';
         t.WhatId = 'opp.Id';
            tasktoInsert.add(t);
        }
    }
    if(tasktoInsert.size()>0) {
        insert tasktoInsert ;
    }
}

 Error:
Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, ClosedOpportunityTrigger: execution of AfterInsert caused by: System.StringException: Invalid id: opp.Id Trigger.ClosedOpportunityTrigger: line 7, column 1: []

Hope you guys can help me.
Thanks in advance,
Mounika.

Hello Community,
 I'm Working on the Bulk Apex Triggers Trailhead and its throwing me the following error.
Question:
Create an Apex trigger for Opportunity that adds a task to any opportunity set to 'Closed Won'.
To complete this challenge, you need to add a trigger for Opportunity. The trigger will add a task to any opportunity inserted or updated with the stage of 'Closed Won'. The task's subject must be 'Follow Up Test Task'.
The Apex trigger must be called 'ClosedOpportunityTrigger'
With 'ClosedOpportunityTrigger' active, if an opportunity is inserted or updated with a stage of 'Closed Won', it will have a task created with the subject 'Follow Up Test Task'.
To associate the task with the opportunity, fill the 'WhatId' field with the opportunity ID.
This challenge specifically tests 200 records in one operation.
Here is my code:
trigger ClosedOpportunityTrigger on Opportunity (after insert,after update) {
    List<task> tasktoInsert = new List<task>();
    for(Opportunity opp : Trigger.New){
        if(opp.stageName == 'Closed Won'){
        Task t = new task();
        t.subject = 'Follow Up Test Task';
         t.WhatId = 'opp.Id';
            tasktoInsert.add(t);
        }
    }
    if(tasktoInsert.size()>0) {
        insert tasktoInsert ;
    }
}

 Error:
Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, ClosedOpportunityTrigger: execution of AfterInsert caused by: System.StringException: Invalid id: opp.Id Trigger.ClosedOpportunityTrigger: line 7, column 1: []

Hope you guys can help me.
Thanks in advance,
Mounika.

i not understanding usage of junction object .

Please explain usage and how to create junction object with a example