Hi Antonio
Decidedly IE gives us a lot of problems instead of simplifying our lives like other browsers.
I thought it was a bug as stated in this link :
Http://www.neunbeere.de/blog/2015/08/bug-in-internet-explorer-that-prevents-drag-drop-operation-in-active-x-controls/

Even installing the unprotected mode IE bombards us with alerts! Which complicates programming.
in principe allowing oledragdrop must be a default mode : must alert anyone using this technic to run IE11 as admin
at opposite , Microsoft makes this as default mod in Edge !
MS must review its copy !

thank you very much.