Hints
From Sage CRM Knowledge Base
Forcing an update of a cached JavaScript file in IIS
Ref: http://www.hanselman.com/blog/ForcingAnUpdateOfACachedJavaScriptFileInIIS.aspx
IIS 404 messages but directory browsing is possible.
Chances are that ASP.Net was set as prohibited in IIS. Re enable to fix.
Application pool Idle timeout set to 43200 (30 days)
401 Unauthorized: Access is denied due to invalid credentials
To fix this open regedit as an admin user and navigate to key
"HKLM\SOFTWARE\Wow6432Node\eWare"
Right click and select permissions and grant your IUSR account full permissions to the eware key
ref: https://community.sagecrm.com/user_community/f/74/t/4281.aspx