Upgraded with Linux installer from 5.5.6 to 6.5.19. Upgrade had no errors.
After restart, I get this error on the main page:
org.apache.jasper.JasperException: An exception occurred processing [errors.jsp] at line [13]
10: <link rel="shortcut icon" href="johnson/fav-confluence.ico">
11: <%
12: JohnsonPageI18NProvider johnsonPageI18NProvider = (JohnsonPageI18NProvider) BootstrapUtils.getBootstrapContext().getBean("johnsonPageI18NProvider");
13: String translations = johnsonPageI18NProvider.getTranslations().serialize();
14: %>
15: <script>
16: window.i18n = <%=translations%>;