It takes 20 seconds to load using WAMP on Windows 10.

And for me, Firefox freezes after a few seconds.

First time I test this plugin. Imho it should prevent choosing any core folder in root except the images one. I.e. it would let choose a custom root folder + images

So, it would be OK if we do

					<field
							name="directory"
							type="folderlist"
							default="images"
							label="PLG_FILESYSTEM_LOCAL_DIRECTORIES_DIRECTORY_LABEL"
							folderFilter=""
							exclude="administrator|api|build|components|cache|includes|installation|language|libraries|logs|media|modules|node_modules|plugins|templates|tests|tmp|bin|cli|layouts"
							stripext=""
							recursive="true"
						/>

In that case we would get with this PR

I am going to close this. It is clearly not practical to have the full recursive folder tree and the suggestion of @infograf768 doesn't work either as it removes the possibility of using media manager on other folders.

It does not make sense to display all core folders in this plugin, but it makes sense to use a custom image folder. So, even if we don't choose recursing, we still should limit the folders displayed in the dropdown to images and custom root folders.

If no one makes a PR, I will.

Whilst looking at this, without applying the patch, I added templates to the Select Directories list. Worked as expected. Then I removed templates and Media displayed an internal error:

It went away after selecting the Local images folder.

@ceford
This means that we do not check for the existence of folders before displaying them.
I think it can be solved, but it is a different issue.

EDIT, looks like we only use
throw new FileNotFoundException; and no message/error
or InvalidPathException which is empty