1. Reinstall Java. Use the JRE offline installer & remove your current Java before you install this version.
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2. Delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
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This will kill all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.

3. Reinstall LW & make sure to use the offline installer (not the recommended one).
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