I deployed a WAR file into $TOMCAT_HOME/webapps by copying the file into the directory, just like I've done a thousand times before. Tomcat detects the WAR and inflates it. I can traverse the directory tree on my server at the command line (it's Fedora).

But when I address the webapp within my client machine's browser, I get nothing but 404 errors. This has happened to the last two deployments of completely separate WARs.

The first was a replacement of an existing WAR. I first deleted the WAR and its inflated directory, and then copied in the WAR which inflated... 404. I deleted everything again, put back the previously working WAR from backup. It inflated and worked.

The second was a completely new, never before deployed WAR... nothing but 404.

Other WARs are working, but now I'm afraid to change anything until I know what is going on. Any clues?

Edit: From my comment you can see that the logs included "SEVERE: Error listenerStart" after the WAR was deployed by Tomcat. There were no stack traces or other errors reported.