I am working on on-premise SharePoint 2013 installed on my local machine. I am facing a strange issue when building custom master page through design manager. I have created a mapped folder for the master page gallery.Whenever I edit any JavaScript/CSS file in the master page gallery(say, some.js) using Visual Studio, the JS/CSS file gets renamed to some HEX file name (803226c7) without extension and the Master Page refers to this name i.e. instead of <script src='some.js'></script> it becomes <script src='803226c7.js'></script>. 

If I use notepad/NotePad++ to edit the file, there is no issue. I want the JS/CSS intellisense, so want to use VS 2013.There is no issue when editing the html master page.

I know this is network related, but unable to figure out why only Visual Studio causes the problem with file in mapped folder of Master Page gall

Hi Suhas R.S,

This forum is about Visual Studio IDE, as your issue is related to your sharepoint master page, I help you move this case to SharePoint 2013 - Development and Programming forum for dedicated support. Thank you for your understanding.

Best Regards,