The VO ErrorBlock() function gives the possibility to set a global error handler. Unfortunately, in .NET this is not more possible as the CLR (the Common Language Runtime) does not supports such a feature.

In a .NET application you need to make extensive use of try - catch blocks and use the relative exceptions to react to runtime errors. You can set a few default handlers for otherwise unhandled exceptions, but that is far away from the VO functionality.

For compatibility, the ErrorBlock() function is there, but the set handler is called by the runtime system only where a begin/end sequence is replaced.

For details please see the post by Robert v.d.Hulst: https://www.xsharp.info/forum/public-product/1418-dtawin-server-exceptions#10445