Link in alert email for PPTX document leads to "File Not Found" - Caused by encoding error

Question

We have an issue brought to our attention by our customers that has me scratching my head.  When our users sign up for an alert on a document library and a PowerPoint document is edited, the link in the alert email looks something like this:
http://Teams/sites/TeamABC/_layouts/PowerPoint.aspx?PowerPointView=ReadingView%26PresentationId=/sites/TeamABC/Shared%2520Documents/SharePoint%2520Service%2520Management.pptx
Although the issue looks like it could be with the double encoded spaces (first encoded is %20, second encoding is %2520), those work fine.  The issue comes from the %26 between "ReadingView" and "PresentationId".  The %26 is an encoded "&". 
If I replace %26 with "&" the url string works fine.  I have tried this in IE, Firefox, and Chrome and the result is the same in each, so it's not a browser issue.
The question then becomes, is the error the encoding when the alert is created and sent or is the error with the http handler in SharePoint that doesn't appear to understand how to handle %26?  With that, any ideas on how to fix this (other than tell
users to edit the url in the browser changing %26 to "&")?
I should mention we are using SharePoint 2010, SP1, plus August 2011 CU, with Office Web Apps. 

Answer 1

Hello,
I think it is because we cannot use "&" in the file name when uploading the file to Sharepoint, we will receive the
message:
The following characters cannot be used anywhere in a site name, in a subsite name, or in a site or Active Directory group name:
tilde (~)
number sign (#)
percent (%)
ampersand (&)
asterisk (*)
braces ({ })
backslash (\)
colon (:)
angle brackets (< >)
question mark (?)
slash (/)
plus sign (+)
pipe (|)
quotation mark (")
You can check this
post on SharePoint forum:, if you have further questions, you can also post the question on the SharePoint 2010 forum
here
Hope above helps.
Daisy Cao
TechNet Community Support