The free version of the Spoiler add-on
has been recently updated to have a new algorithm of displaying spoiler. Now it will be displayed "on click" i.e. when the hidden text is clicked. Mostly this was implemented for touch-screen devices. This feature has been sponsored with the help of TG Comics
If you'd like to install/update the new version, you need older Spoiler tags converted to a new format. Use the Conversion script
for this. Before you run this script, make sure the option $convertMode (in the script itself) is set to FALSE. This mode will allow you to overview all current spoiler tags and make sure the conversion will execute properly. Afterall, set it to TRUE and re-run the script again. All older tags should be converted; if you run the script yet again, you should see 0 results.
Good luck :)