@alexclau77
I noticed 2 things.
1.This URL only work with InPrivate mode of browser.
2.This direct link is not work if I copy and paste.
There is comments in the field notice (Field Notice: FN74146 - Limited Number of Cisco Catalyst Routers Can Experience Memory Failures - Hardware Upgrade Available - Cisco)
Important: For security reasons, you must click the Serial Number Validation Tool link that is provided in this section. Do not copy and paste the link into a browser. Use of the Serial Number Validation Tool URL external to this field notice will fail.
You need to open field notice first with InPrivate mode, then click URL in the page.
