Broken SCOM Web Console URLs?

I come across a situation where when i click on the web console URL from a SCOM notification email such as this one: http://<SCOM Web Server>/default.aspx?DisplayMode=Pivot&AlertID=%7b07aac5b0-4cf8-411f-b5a0-cb0075dc0f31%7d

I get a HTTP 500 error:

I had to change the URL from http://<SCOM Web Server>/default.aspx?DisplayMode=Pivot&AlertID=%7b07aac5b0-4cf8-411f-b5a0-cb0075dc0f31%7d to http://<SCOM Web Server>/default.aspx?DisplayMode=Pivot&AlertID={07aac5b0-4cf8-411f-b5a0-cb0075dc0f31} to make it work. It’s quiet painful as %7b and %7d comes as a part of SCOM WebConsole Link variable…

For this particular environment, I found out it was caused by Forefront TMG server was blocking encoded URLs for this website.

After unticking Verify normalization and Block high bit characters in the TMG rule, the encoded URL started working!