No images loading on Safari or Chrome

Hello..

I have an old Macbook pro (2009) running OS X El Capitan (10.11.6). For some reason it is no longer showing any images on any websites; this is on both Safari and Chrome (so no browser related). I've read forums and cannot seem to find any answers.

This happens on ALL websites and I get a range of different reasons when inspecting the element. These are as follows:

• Failed to load resource: the certificate for this server is invalid. You might be connecting to a server that is pretending to be "website.address" which could put your confidential information at risk.

• Failed to load resource: the server responded with a status of 403 ()

• Failed to load resource: the server responded with a status of 401 ()

• Failed to load resource: the server responded with a status 404 ()

• [Error] The source list for Content Security Policy directive 'script-src' contains an invalid source: ''strict-dynamic''. It will be ignored.

• Failed to load resource: Not allowed to authenticate

This is what shows where the images are:

This is on all websites including well known sites that should not be a risk.

Appreciate anyone's help as I've been trying to fix this now for weeks with no success.

Thanks

Toni