Click on Plain radio button and click on Save changes. After this check the site, if it is working well then again click on Post name to change to a SEO friendly URL.
If still getting problem, send us WordPress admin login details of your site at [email protected], so we can check the site and solve your problem.
The plugin ‘WP Content Copy Protection & No Right Click (premium)’ is conflicting and
after deactivating this plugin website is working well with SEO friendly URl in google crome.