Does this happen the same way for you for all of the presets? Can you make any edits to the presets and successfully save them? If so it would indicate an issue that is specific to the preset you created. If this is the case post back and let us know what you are doing when editing your preset that is not working, if a gif is needed to reproduce this result please include it.
We can check on this to see what the problem might be. If this is not the case and you are getting this error regardless it could indicate that there is a corruption somewhere or something like that. If that is the case you would first want to check the cache file and next you would rename the config folder. Here are links to the steps for these: