Small issue with CustomPress, but it still worries/annoys me

Hi, I noticed that whenever I use F12 on my wp-admin to enter browser developer mode, I always get the following console error:

Can this be fixed? I think it's probably just add that javascript file.

Now to the real problem I think this is giving me:
I started noticing this because whenever I try to add media to a post/page, the media files appear with lower opacity, as if they were loading or disabled. (They work fine, it's just annoying and my client hates it).

Also, noticed that the UL that contains the media list has this status: <ul tabindex="-1" class="attachments ui-sortable ui-sortable-disabled ui-state-disabled" id="__attachments-view-115" aria-disabled="true"><li tabindex="0" role="checkbox" aria-label="LOGO-a-Color" aria-checked="false" data-id="858" class="attachment save-ready">

As you can see there, it has a class named: "ui-state-disabled", which is responsible for the low opacity. The only reason I could think of that could be causing this is this error, since it's the only one I have on console (so I'm hoping that's the problem).

Anyways, can you help me with this? Or atleast fix that javascript not found error so I can atleast discard this?