How to resolve "enter the password for credential storage" issue?

Question

So I am playing around with fiddler web proxy. I need to decrypt https traffic. So I am trying to put the fiddler root CA cert in my device trust store. But it keeps asking me "Enter the password for credential storage". If i enter anything and click enter I see an Toast message saying

Credential storage has been erased

and the password prompt comes again. This goes on in a loop. For the record I have selected "Wifi" as the Credential use instead of "App n VPN" (not sure of that matters).

Next wired thing that I noticed is that after each prompt the description changes for label

The package contains

The value for it increases each time the password prompt is shown. For eg - 3 CA certificates, 4 CA certificates and so on...

As much as I want my device to accept this certificate I would appreciate if someone could explain the "credential storage" concept and the weird increment of CA certs text.

Intercepting Android network calls using Fiddler Web Proxy

Answer 1

I could now install the certificate. I had to disable pattern screen lock and try installing certificate again. This time it asked me to setup security - pin or password.

That I did and cert got installed. Got the solution from android central forum.

http://forums.androidcentral.com/google-nexus-7-tablet-2012/301151-credential-storage.html

I guess that thread is for VPN but same solution works for Wifi certs as well. Please do add if anyone has any additional info on this or workaround.