If you have recently started seeing the "In order to continue using OpenSubtitles service you need to login" error then use the guide below to fix the issue which will stop you from downloading subtitles for your language.
OpenSubtitles Fix for Kodi
- Register at OpenSubtitles.org
- Wait for confirmation email and then click on confirmation link
- Open Kodi
- Select Settings (cog icon top left)
- Select Add-ons
- Select My add-ons
- Select Subtitles
- Select OpenSubtitles.org
- Select Configure
- Add the Username & Password you registered at the OpenSubtitles website
- Select OK
You should now have no issues with OpenSubtitles in Kodi