Problem with clients connection - Openfire 4.0.2

Hi! I installed the Openfire 4.0.2 using .deb. At first,  Java wasn't installed in my server so, i installed the opendjk-7-jre. When i did a test with Spark (after with Pidgin and Xabber), the clients hanged at 'trying to reconnect'. In Pidgin, the message was 'Internal Server Error'. Reading here in the forum, some people suggested that updating to java 8 would fix the problem but, didn't work with me. In Server Configuration Page, even after purged the java7, the message in Environment is 1.7.0_101 Oracle Corporation -- OpenJDK 64-Bit Server VM.

Specs:

OS - Debian 8 - 64 bits

Java:

Java version "1.8.0_91"

Java(TM) SE Runtime Environment (build 1.8.0_91-b14)

Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode)

So: how can i reinstall (if possible) openfire using Java 8? Or, how can i fix the problem?