Java NoSuchAlgorithmException - SunJSSE, sun.security.ssl.SSLContextImpl$DefaultSSLContext

This is one of those misleading issues coming from a log trace which does not tell you the real cause. Most likely if you scroll up in the log file you will find something like:

Caused by: java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: ... Caused by: java.security.PrivilegedActionException: java.io.FileNotFoundException: /opt/tomcat/certs/customcert.p12 (No such file or directory) ...

As a general rule restart the jvm and pay attention to absolutely all errors ;-)