Q:

Can't activate Visio 2013 MSDN

I have an MSDN subscription and I've installed Visio 2013.   I am not able to activate the product and it has reduced to a read-only state. 
Any attempts to activate or "Switch Account" are met with "Sorry, we are having some temporary server issues."   I've found a few posts referencing removing an office-related key from the registry but this has not helped. 
At one point I believe I'd also heard that our network might be blocking activation, but don't have a handle on how that would be coming into play exactly (if at all). 
Have others encountered and (hopefully) found a fix to this issue? 

A:

Go to Control Panel -> Programs and Features -> Microsoft Visio Professional 2013
Right click on Microsoft Visio Professional 2013 and click on "Change"
Then select "Enter a Product Key" and supply your 25 digit licence key to activate. 

A:

Here is a little more detail on the Control Panel/Programs and Features method for entering product codes. 
This worked with Office 2010 previously installed and then a later Visio 2013 Pro installation that didn't provide the activation dialog. 
In Programs and Features
Right click Microsoft Visio Professional 2013
You'll see Uninstall (default) and Change.  Select Change
You'll get a dialog with these options

Add or Remove Features    
Repair
Remove
Enter a Product Key (voila!) 

Select Product Key and the rest goes as expected. 
Footnote: I spend 45 minutes in six conversations with four different Microsoft support teams trying to fix this.  None knew how to address the issue.  

A:

I had the same problem.   To activate I had to go to "Control Panel\Programs and Features\Microsoft Visio Professional 2013" and choose the "repair" option; you will be asked to insert your product key.   Now my Visio is activated and I can create new diagrams, but I continue having problems using online options.