If you want to fix the behavior of the "Edit using Notepad ++" right button, first go to the next item:
HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\Notepad++
If the default value is:
{00F3C2EC-A6EE-11DE-A03A-EF8F55D89593}
then go to:
HKEY_CLASSES_ROOT\CLSID\{00F3C2EC-A6EE-11DE-A03A-EF8F55D89593}\Settings
Among the elements should be Custom REG_SZnothing after it. Change the value to -nosession -multiInst.
Custom REG_SZ -nosession -multiInst. , -nosession -multiInst .