When trying to edit fields on contact summary using AJAX hover method, the fields don't open up properly for editing (scroll bars are sometimes missing, and not enough space is revealed). On clicking save, I get a fatal error: "Invalid classname".
I'm on Drupal but not using JS or CSS aggregation.
I had thought this was due to upgrading to 4.7.15. But my dev site (same version) does not have this problem.
[Edited to add more info]:
In the browser console, when loading the contact record I get this error:
Refused to execute script from 'https://my.site.com/index.php?q=civicrm/ajax/responsiveadminmenu/7242/en_US/1/2ChmFGPv&1' because its MIME type ('text/html') is not executable, and strict MIME type checking is enabled.
Then when clicking on a field such as email or phone I get:
jquery.js:339 Uncaught SyntaxError: Unexpected token <
These errors do not come up on the dev site so I suspect they are related.