yoshimitsu1234 on "[Plugin: W3 Total Cache] Changes in forum attachment & editor on enabling cache"

Have a look at these 2 screenshots.
with w3tc enabled
with w3tc disabled
As you can see after enabling w3tc plugin pdf attachment icon is gone and also its look. Also at bottom you can see post editor buttons which has changed its look. Also link button in post editor does not work.
I am using bbpress, buddypress, GD bbpress attachments and GD bbpress tools plugins.

https://wordpress.org/plugins/w3-total-cache/