Cannot transfer money to another account

[nxqd]

I cannot send payment to my mother's account. I could send a week ago but not now. The error is : 

There's seems to be a problem

We can’t send your payment right now. If you keep running into this issue, please contact PayPal.

What could go wrong here ? 

[sharpiemarker]

Please contact customer service for assistance: https://www.paypal.com/us/selfhelp/contact/call

This is user to user forum.  We do not have access to accounts to trouble shoot.