Moved Wordpress to new server, strange Javascript error (no inline JS?)

I just moved a WP site to another server and I get this error in my console:

Refused to execute inline script because it violates the following Content Security Policy directive: "script-src 'self'". Either the 'unsafe-inline' keyword, a hash ('sha256-...'), or a nonce ('nonce-...') is required to enable inline execution.

When searching for a solution, I only see things about Chrome extensions.

What can this be, all of a sudden?

I tried updating Jquery to the latest version, but it did not help. It's very strange, I can't pinpoint it. On my development machine and at the new location the site bloats. Luckily the production site is still functioning.

Edit:

This solution works partially: http://ift.tt/1rOSmtC. Basically, you have to add this line to a .htaccess file:

Header set Content-Security-Policy "allow 'self'; media-src *; img-src *; script-src 'self' 'unsafe-inline' http://ift.tt/Q55qZD http://ift.tt/rzP4g5; style-src 'self' 'unsafe-inline';"

But partially! Now the CSS bloats:

Refused to load the stylesheet 'http://ift.tt/11KTbap' because it violates the following Content Security Policy directive: "style-src 'self' 'unsafe-inline'".

But the question remains: why is this happening out of the blue?