I have done everything they have aske for still this error isn't solving , i have crossed checked in salesforce classic too verify weather its a matrix report or not and i have grouped them as they have asked still there is some issue with it .

Hi @Sathvika Totakura

sure.. 

So basically i had to create a new org to slove this issue usually u vl get this issue even after creating a new org but it vl be slove if u create a new report vd the given name nd provided filters  

Once we recreate it (we shouldn't clone it) delete the old report vd same title nd check challenge