There are a lot of small issues. Some of them should be listed here:

• You are using a method Open() in any of your VO windows classes? This will not compile anymore because the Window class has a variable oPen that conflicts with this method name
• you are using '-' in resource paths? For example something like this:

[code]icoFett Icon c:\cavowork\brandnamic\ba-erp\icons\Fett.ico[/code] You need to surround the filename with double apostrophes like this: [code]icoFett Icon “c:\cavowork\brandnamic\ba-erp\icons\Fett.ico”[/code]

• _CodeBlock class: if you are using subclasses of the _CodeBlock class: the Eval method in VO is using the Clipper calling convention, the one in the Vulcan runtime the Strict calling convention
• Functions or methods that pass an object by reference, and you pass a inherited object. This code

[code]function CleanUpServer( oServer ref DataServer ) as void oServer:Close() oServer := null_object return[/code] compiles in VO without any issue when you call it with any subclass of DataServer or DBServer. This is very dangerous and therefore it will not work anymore in X#.

• Local static in VO is currently (X# 1.1.2) not recognized by the X# compiler, but is valid in VO. Change it to static alone in your VO code.