Error with Gutenberg

I’ve just installed Gutenberg on my website. I received this error when I opened Gutenberg for the first time in my WP admin.

Failed to load plugin url: https://www.beckerstudio.com/wp-content/plugins/otw-portfolio-manager/include/otw_components/otw_shortcode//js/langs/en.js’

Everything seems to be working but I haven’t tried adding a new portfolio or portfolio items. You may want to look into this.

Expected behavior
I didn’t expect an error.

Desktop (please complete the following information):

OS: Windows 10
Browser: Chrome
Version: Version 67.0.3396.99 (Official Build) (64-bit)
Additional context

Gutenberg: Version 3.4.0
Portfolio Manager for WordPress: Version 2.3 | By OTWthemes.com