I've exhausted all efforts thru the user forum. Maybe someone can help me?
I want to include values of custom fields in my email notifiactions.
I was successful (at first) by using some code from another user:

#foreach ($cfv in ${issue.getRelated("ChildCustomFieldValue")})
#set ($cf = ${cfv.getRelatedOne("ParentCustomField")})
#if (${cfv.getString("stringvalue")})
	<tr><td width=20%><b>${cf.getString("name")}:</b></td><td
width=80%>${cfv.getString("stringvalue")}</td></tr>
#elseif (${cfv.getString("textvalue")})
	<tr><td width=20%><b>${cf.getString("name")}:</b></td><td
width=80%>${cfv.getString("textvalue")}</td></tr>
#elseif (${cfv.getString("numbervalue")})
	<tr><td width=20%><b>${cf.getString("name")}:</b></td><td
width=80%>${cfv.getLong("numbervalue")}</td></tr>
#end
#end

Well, that seemed to work, but then I found that NOT ALL custom fields were handled by the above code. Specifically, drop down values. However, it didn't bother me so much that for some custom fields the values displayed as internal codes. The problem was one project that had a custom field of type 'project picker'. email notifications for that project caused the template to break with an error:
Invocation of method 'getLong' in class org.ofbiz.core.entity.GenericValue threw exception class java.lang.ClassCastException : java.lang.Double at
org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:246
) at ... etc. ...
I tried putting in #else code to handle some cases, I tried putting in code I found from Anton in the user forum:

#elseif ($cf.getLong("fieldtype").intValue() == 1 ||
$cf.getLong("fieldtype").intValue() == 3 ||
$cf.getLong("fieldtype").intValue() == 5)
	<tr><td width=20%><b>${cf.getString("name")} : </b></td><td
width=80%>${cfv.getString("stringvalue")}
#elseif ($cf.getLong("fieldtype").intValue() == 2)
	<tr><td width=20%><b>${cf.getString("name")} : </b></td><td
width=80%>${cfv.getLong("numbervalue")}
#elseif ($cf.getLong("fieldtype").intValue() == 4)
	<tr><td width=20%><b>${cf.getString("name")} : </b></td><td
width=80%>${cfv.getDate("datevalue")}

all to no avail. I really would like to get this working - or at least not broken. I've looked at the Velocity user's manual and scoured the source code, but I can't find how to do this.
As a side note (I can log an issue if you like), I noticed that when viewing an issue that has been moved between projects, the "Change History" also shows the internal project ID rather than the project name, so even within the web interface, it looks like internal ID's still show up sometimes.