You cannot use a pound character in a file name for a hyperlink in an Office program
微软官方解决方案

Hyperlink with pound sign in filename
 

 hyperlinks not working with pound/hash sign in folder name
 

默认情况下把#当成 anchor（类似bookmark），所以会报错。
 

How to Create Hyperlinks Containing Spaces
 

HTML中超链接地址中 "&" 链接符可能导致的问题

HTML URL编码参考手册
 

Using Outlook Links
 

Outlook Hyperlinks Fail to Work 

Microsoft FixIt 50388 - Hyperlink error message in Outlook

Fix Restrictions Error When Clicking Hyperlinks in Outlook or Other Office Programs
 

Pound sign displaying problem in outlook in asp.net

 

http://www.winhelponline.com

www.officekb.com

http://www.outlook-tips.net/

www.officetooltips.com 

http://www.slipstick.com/

http://www.msoutlook.info

http://www.outlookforums.com/