When you log in your Juniper SRX device using the web interface you may experience a strange problem where whatever or wherever you click you get a popup saying “Your Session has expired. Click OK to redirect to login page”.
The problem is that the SRX has no more free space to create new web pages so it just says Your session has expired.
When you check the storage of the device you can see a very strange thing of Available memory being overused (-25.6 MB in my case and capacity of 108%).
You can check the available storage using this command:
show system storage
To solve the problem you will have to do a system storage clean-up using this command:
request system storage clean-up
It will list a bunch of files that you probably don’t need.
After that the web console or the JWeb interface is working again.