A UNIX System message send or receive error was encountered while attempting to satisfy the service request selected on the current form. The error is something other than EINVAL or EAGAIN, which are reported on separate messages. Possible causes of this error are EACCESS, which would indicate that the queue permissions of the server have been changed to deny access to the user running mio, or EFAULT, which would indicate a memory corruption problem in application routines linked into mio.