Firefox 52 not supported to java plugin

From Firefox Version 52, (the standard version), the support to java plugin has ended, except for Adobe Flash.


Workaround (until 2018):
Install the 32bits of Firefox Version 52 ESR (Extended Support Release)


JDK8u111/112 – MD5 is no longer considered secure

Oracle JRE will no longer trust MD5-signed code by default

Beginning with the April 2017 Critical Patch Update, JAR files signed using MD5 (RSA algorithm) will no longer be considered as signed by the Oracle JRE.

Oracle Java SE 8u131 which will be released with the April 2017 Critical Patch Update.


Affected applications: Java applets, or Java Web Start applications.

To check your app/jar file:

jarsigner -verify mySynopticApp.jar

To remove any existing MD5 signatures first before re-signing using the zip utility as follows:
zip -d mySynopticApp.jar 'META-INF/*.SF' 'META-INF/*.RSA' 'META-INF/*.DSA'