In this case, you can avoid the error by sideloading the plugins that you want to install. Plugin Manager Plugin is busted – Under certain circumstances, you can expect to see this issue occurring due to an issue with the Plugin Manager feature included with Notepad++.In this case, you should be able to fix the problem by installing the newest version of Notepad++. Outdated Notepad++ version – As it turns out, you can also expect to see this particular issue occurring in those situations where you’re using a severely outdated Notepad++ version that’s not compatible with Windows 10.To fix this issue in this case, you’ll need to enable the required TLS technology from the Advanced Settings menu of Internet Options.
Required Transport Layer Security is Disabled – Keep in mind that if you are seeing this error while attempting to install a legacy plugin, chances you are missing a key transport layer security feature required by the plugin.In this case, you can attempt to install the plugin via the Plugin Manager module inside Notepad++. The plugin cannot be installed conventionally – If you’re attempting to install a plugin via an external managed, chances are it’s failing because it’s not compatible with sideloading.As it’s been confirmed by a lot of affected users, you can resolve this problem by forcing admin access to the launcher. Missing admin privileges – One of the most common situations that will spawn this issue with Notepad++ is a situation in which the application doesn’t have enough privileges to allow the modifications of existing files.