An update doesn’t work for me either. A fresh installation works.
Maybe Michael can do something with it, I get the following errors if I copy Pulse 5.3.1 over 5.3
**Fatal error** : Uncaught LogicException: An invariant has failed in D:\webserver\www\pulse53\pulsecore\dbc.php:12 Stack trace: #0 D:\webserver\www\pulse53\pulsecore\store\base.php(79): pulsecore\invariant(false) #1 D:\webserver\www\pulse53\pulsecore\store\gallery\pile.php(37): pulsecore\store\Base::extract_relative_directory('D:\\webserver\\ww...') #2 D:\webserver\www\pulse53\pulsecore\tags\social_exposure.php(49): pulsecore\store\gallery\Pile->__construct('D:\\webserver\\ww...') #3 D:\webserver\www\pulse53\pulsecore\tags\social_exposure.php(23): pulsecore\tags\SocialExposure->generate_html(Array, Array) #4 D:\webserver\www\pulse53\index.php(372): pulsecore\tags\SocialExposure::execute_tag(Array, Array) #5 {main} thrown in **D:\webserver\www\pulse53\pulsecore\dbc.php** on line **12**