I tried installing the Kodi add-ons Maps Browser and Weather Underground from within the Kodi UI, and checked the log (/var/lib/kodi/.kodi/temp/kodi.log) when it did not seem to work. There I found messages like this:

23:55:36.233 T:140104317466816 ERROR: CCurlFile::Open failed with code 404 for http://repo.parabola.nu/other/kodi-libre/addons/krypton/script.maps.browser/script.maps.browser-1.0.0.zip.md5
23:55:36.234 T:140104317466816 ERROR: Open - failed to open source <http://repo.parabola.nu/other/kodi-libre/addons/krypton/script.maps.browser/script.maps.browser-1.0.0.zip.md5>
...
00:12:59.075 T:140104317466816 ERROR: CCurlFile::Open failed with code 404 for http://repo.parabola.nu/other/kodi-libre/addons/krypton/weather.wunderground/weather.wunderground-6.0.0.zip.md5
00:12:59.075 T:140104317466816 ERROR: Open - failed to open source <http://repo.parabola.nu/other/kodi-libre/addons/krypton/weather.wunderground/weather.wunderground-6.0.0.zip.md5>

The zip files themselves are available at the mirror, but the MD5 checksum files indeed seem missing, see e.g. the directory listing here:
https://repomirror.parabola.nu/other/kodi-libre/addons/krypton/weather.wunderground/