Warning 
1.
Navigate to the Configure > Protocols > HTTP > Cacheability tab.
2.
In the Required Headers area of the Behavior section, select one of the following:
*
An Explicit Lifetime Header to cache only HTTP objects with Expires or Cache-Control headers.
*
A Last-Modified Header to cache only HTTP objects with Expires or Last-Modified headers.
*
No Required Headers to cache all HTTP objects (no specific headers are required). This is the default.
3.
Click Apply.