Membership Page Has a Wait Message

I am trying to clean up the Membership Page, and every time I try to delete names, I get a "Wait" message. Then when I exit the page, I receive another error. Please see attachments. This is the only page I am having issues with. I need help with this. Thank you.

This issue is caused because there are too many inactive memberships on the page. We can assist you in deleting many of these. Would you like us to delete all that have been inactive for more than 1 year?

Yes, you can delete those who have been inactive for over a year. I can't seem to go in and delete these, as I always get the "Wait" message. Hopefully, when you delete some of these I will no longer receive the "Wait" message. Thank you.

Your delete request has been completed

Thank you. Things are running more smoothly and I do not receive a "Wait" message.