Problem with user manager database in CCR

Hello good day, I have two CCR1036-8G-2S + in both CCR I have mounted the user manager and continuously sends the following message:

failed to change session: disk I / O error
transaction failed to commit: can not commit - no transaction is active
failed to commit transaction: failed to commit transaction: can not commit - no transaction is active

after the error and can not authenticate anyone and mikrotik stays in read mode and must be restarted to rise again, sometimes I have to restart 2 times, the user manager I mounted both locally and by usb and behaves like, anyone can help me? or has been the same?

Greetings and thanks