Hi Terry,
I had this issue too. It seems to related to the character case of the ‘SeaSP-Community-Edition’ bit in the URL. The plugin actually installs itself as ‘plugins/sea-sp-community-edition’.
To workaround this for now I have renamed the folder to ‘plugins/SeaSP-Community-Edition’ via FTP and re-activated the plugin so that this bootstrap link works. Not sure how/when this will be fixed by the devs, likely they will change the link itself to the lowercase version, but I didn’t want to edit any of the plugin files.