If you have received the error "Please contact BlackSpigotMC. 0x0" with your server failing to start, it means you have downloaded a cracked plugin from BlackSpigot. We do not recommend that you download cracked plugins, as they may not be safe for your server and the developers are not being supported. To fix the error: 1) Identify which plugin(s) is/are causing the problem by removing all plugins one by one, or determining which plugins are paid plugins that you have not paid for, and remove them. 2) Buy the plugin on Spigotmc.org to support the developer and stop this from happening in the future.