KB40439: "Please enter a valid value for `Physical Address`" is seen when creating an email address containing character '#' in it from MicroStrategy Web 9.x and 10.x

SYMPTOM:
 
When configuring an email address with `#` in it from Strategy Web 9.x and 10.x, the following error message is seen after clicking on "Add to recipients" as seen below:

 
CAUSE:
 
This is a known issue in Strategy Web 9.x and 10.x
 
WORKAROUND:
The email address can be created without any problems from Strategy Developer 9.x and 10.x as seen below:

 
Once created in Desktop, this address can still be used in Web when sending subscriptions.