Cause:
This error is an 'information' error from Oracle, indicating that the current operation has been cancelled.
This error will be generated if the user cancels the current operation. It can also be generated in response to other errors (such as timeouts).
Remedy:
If this error is generated in response to the user cancelling their current operation then the message is correct and no remedial action is required. (Although it may be pertinent to understand why the user cancelled the operation.)
If the error is preceeded by any other error then it is likely that it is the preceeding error which needs to be investigated.
Timeouts (whether explicitly or implicitly specified or reported) are a frequent cause of ORA-01013. This can be difficult to identify because a timeout may not be explicitly reported as part of the error.