Not able to show related records - salesforce

Question

I have two custom objects, X and Y.
The object Y is related to X by lookup YretatedX__c.
I am trying to show all Y related to X y standart page of X whith a visualforce.
Visualforce:
<apex:page standardController="X__c" extensions="related_list">
<apex:detail relatedList="true">
<apex:relatedList list="Y__c" subject="{!AllRelated}"/>
</apex:detail>
</apex:page>
Apex Class:
public class related_list {
private X__c x;
private Id idX;
public List<Y__c> AllRelated = new Y__c[]{};
public related_list(ApexPages.StandardController controller) {
this.x=(X__c)controller.getRecord();
idX = this.x.Id;
}
public List<Y__c> getAllRelated() {
AllRelated = [SELECT id FROM Y__c WHERE YretatedX__c =: this.idX];
return AllRelated;
}
}
In X page, the visualforce only shows:
Invalid parameter value "[a120E0000001234567, a120E0000007654321]" for parameter "id"
This Ids are valid for Y objects retated to this X object
I tried a lot, but I can find a solution.

Answer 1

I think you're not understanding the attributes of the apex:relatedList component in Visualforce.
Refer to this:
https://developer.salesforce.com/docs/atlas.en-us.pages.meta/pages/pages_compref_relatedList.htm
Note that you don't actually need to query for the records to display them with the component.
All you need is this:
<apex:relatedList list="Contacts"/>
You need to specify the Relationship Name for the list attribute
You don't need to specify the subject (the subject is the record who is the Parent of the list you are trying to show) as this would automatically be populated by the Standard Controller
Hope that helps.

Answer 2

I found a solution using <apex:pageBlockTable instead of <apex:relatedList
<apex:page standardController="X__c" extensions="related_list">
<apex:pageblock id="CustomList" title="Y" >
<apex:pageBlockTable value="{!AllRelated}" var="y" rendered="true">
<apex:column value="{!y.id}"/>
</apex:pageBlockTable>
</apex:pageblock>
</apex:page>