Hey,
We also provide hosting services so I know it very clearly that where you are facing the problem, still I need the URL of your website to check it properly and then I'll solve this issue within a couple of hours.
As you have paid membership pro plugin correct?
then you are using Paypal and other payment gateways, okay?
nextly when payment expires or canceled then IPN notifications is not reaching to paid membership pro and that error which you described is showing, alright?
So we can do this and let's initiate a chat to discuss over it.
Looking forward to it.
Thanks and Regards,
Ravid