XF 1.4 Error installing on WAMP 2.5 development server

[PCC]

I'm getting the following error when trying to install v1.4.3 on a WAMP 2.5 development server.

Apache 2.4.9
PHP 5.5.12
MySQL 5.6.17

Everything checks out fine then I click the Begin Installation button and it creates the tables and then I get this error.

Error
invalid_class_x

Any ideas why this might be happening? I have uninstalled and re-installed WAMP server and get the same result. I have also tried EasyPHP and XAMPP servers with the same result.

 

[Mike]

This likely points to the files not being uploaded/extracted correctly. I would redo whatever you did with the files and try the install again.

 

[PCC]

Yep, that did the trick. Thanks!