The error 1020 is one of the errors you could receive while visiting a site in your browser (Google Chrome, Mozilla Firefox, etc.). The following content offered by MiniTool Solution shows you what causes Cloudflare error 1020 access denied & how to fix. The error 1020 is one of them it occurs when you are trying to access a Cloudflare protected webpage. You may run into a series of errors while trying to visit a page using browsers they’ll stop you from seeing what you want.