Hi chittasn,
For this issue, may be the browser or the customization applied to the SharePoint or any other changes effect your site.
You can try to delete the item in other lists to check whether the issue occurs. If all lists have this problem, may be the browser has problem, please try to test it with other browsers. If only this list has the issue, would you please try to check whether
you have any modifications on the page? If so, you can delete all the changes to check whether the delete operation works.
Best Regards,
Qiao Wei
TechNet Community Support
