Recently, I came across an issue of experience editor not working. After a few trouble shooting steps I found following lines in Showconfig.aspx

In a vanilla sitecore installation it should be like

So I read through the DAM configuration document and found following

SERVER CONFIGURATION
For assets to be rendered in the Sitecore editor, add the following snippet to the sample
rendering configuration file ( an .xslt file found on the Sitecore host server
\SiteCoreROOT\Website\xsl\sample rendering.xslt).

So added following lines to “sample rendering.xslt”

After adding this line my sample rendering.xslt looks like