If you forgot to download your spoiler or just don't know where you saved it, the OoT Randomizer FAQ provides a few options on how to recover it.
Spoilers generated with the OoT Randomizer versions prior to 7.1 are not guarenteed to work. This is because the developers have changed the naming conventions for the spoiler information in the past, and the current parser does not include region names from older version of the OoT Randomizer.
If this is a major issue for you, please feel free to make a feature request on Github! If it would be of benefit to people I'd be happy to work on fixing this issue, but I can't really justify taking the time to do so unless I know that anyone cares :P.