Check to ensure that the MS SQL Agent is set to start Automatically and is running.
As per Microsoft: "This message indicates that an I/O error was reported by the operating system after a file handle was successfully opened. The error occurs when reading from or writing to a device specified as part of a BACKUP or RESTORE command, often when there is not enough disk space available for a write operation. This error may also be seen if third-party software that uses a virtual device to perform SQL Server backups cancels the operation.
User Action: The steps to take will depend upon the operating system error received.
1. Verify that the specified path has sufficient disk space for the file.
2. Test to see if the problem is isolated to this particular server, path, or file.
3. Run hardware diagnostics to verify that the media specified in the path is healthy.
4. If the operating system error only returns a number and not any text, you can open a command prompt and execute NET HELPMSG with the operating system error number as the parameter. In many cases, this will return text that can help you to isolate the problem.
5. If you received this error while using third-party backup software, check that application's logs to see if it canceled the backup operation, and if so, why".
See the link to "Microsoft event 18210 from source MSSQLServer" for additional information on this event.