Can you have a look in the ZAP log to see if any errors are generated?
On Windows this will be under your user directory in OWASP ZAP/zap.log
On Linux it will be in ~/.ZAP/zap.log

As you spotted...

And we've now released ZAP 1.3.1
This is a bugfix release and contains no new functionality.
As before it can be downloaded from https://code.google.com/p/zaproxy/downloads/list

Many thanks,
...

Hi folks,

Version 1.3.0 of the OWASP Zed Attack Proxy (ZAP) has now been released.

This release adds the following main features:

Fuzzing, using the JBroFuzz library
Dynamic SSL...

You beat me to it!

Significant changes in 1.2.0:


Memory leaks have been fixed in the active scanner and spider
External applications can now be invoked from the Sites and History tabs
...

Ooops, sorry.
I'll include OWASP Zed Attack Proxy Project - OWASP next time!

Cheers,

EDIT:

Just had a look at bt4rc2.
I was expecting to see zap1.0.0 as it was added in revision...

Version 1.1.0 of ZAP has now been released.

This release adds the following main features:

OWASP rebranding
Brute Force scanner c/o the OWASP DirBuster project
Port scanner
Active Scan tab...

Hi espreto,

If you want to work on it then I'd recommend getting in touch with the OWASP Global Projects Committee (global-projects-committee@lists.owasp.org).
They may well allow you to take...

Thats great :)

FYI ZAP has now been accepted as an OWASP project, and its new home page is here: OWASP Zed Attack Proxy Project - OWASP

Many thanks,

Psiinon

Hi SWFu64,

Glad you like it :)
If you (or anyone else) have any feedback about ZAP I'd be really interested in hearing it, either via this thread or the developer group.
e.g. what do you like,...

My comments about Ratproxy, skipfish and Fiddler2 + Watcher are based on my current understanding of these tools - please correct me if I'm wrong about anything :)

To quote from RatproxyDoc -...

The Zed Attack Proxy (ZAP) is a penetration test tool designed to be used to make web applications more secure.

While ZAP can detect some security issues automatically, it is primarily designed...