Plugin fails to install, but site's working fine

Hi there,

I installed this plugin (https://performancing.com/wordpress-plugins/) and I tried activating it. In a white page, it said “Invalid Header”

So I hit back on my browser and I see that the site is working fine, my back-end is loading. The plugin’s not listed on my plugins list on my WP dashboard but when I dug into my WP-content directory using my FTP, I did see that the folder has been created and the plugin files are there

now will I face a problem in the future? I mean, will this conflict? Has my wordpress installation automatically disabled this plugin?

Please share your thoughts.