**This answer is only working with Xpert.ivy 5.0 and higher.**
Add the following code (filter which sets the caracter endocing to UTF-8) to your web.xml under webapps/ivy/WEB-INF (Designer and Server):
<filter>
<filter-name>setCharacterEncodingFilter</filter-name>
<filter-class>org.apache.catalina.filters.SetCharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<async-supported>true</async-supported>
</filter>
<filter-mapping>
<filter-name>setCharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
Add to all your jsp layouts/templates (under /Layouts/ in the cms) or to jsp pages in the webcontent the following code to the first line:
<%@page contentType="text/html; charset=UTF-8" %>
Also change the meta-inf html header to the right encoding:
<head>
...
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
...
</head>
**Warning: There is an issue #24706 with file upload (multipart form-data). This does only work for special characters (e.g. umlauts) from Xpert.ivy version 5.0.8, 4.3.20 5.0.8 and higher**