Cors Exception When Adding Gliffy Or Draw.io Diagram Into Global Template

[i can]

I tried to add a global page template using cloud confluence console. (/wiki/pages/templates2/listglobaltemplates.action) I wanted to add gliffy and draw.io macros but i couldn't do it because of the Cors error. 

When i try to save gliffy file, it doesn't work and i get this on the browser console:

Access to XMLHttpRequest at 'https://go.gliffy.com/go/api/setutmcookie?' from origin 'https://confluence-connect.gliffy.net' has been blocked by CORS policy: The 'Access-Control-Allow-Origin' header has a value 'null' that is not equal to the supplied origin 

When i try to add draw.io, i get this on the browser console:

Failed to validate origin 

Also, i tried adding space template but it doesn't work either. I couldn't find any security configuration for it. So, how can i add these diagrams into my global templates.

Chrome version 75.0.3770.100)

[MJ · Accepted solution]

Information regarding system requirements for hosting Confluence in a self hosted environment can be found here