Is this in a LotusScript agent? Without a bit more context or tags added to the post it's hard to be sure. If so, it's a feature introduced with the newer LotusScript editor.

 

If so, Forms and Views which use the old editor don't save with errors as far as I know. Agents and Script Libraries do, which is good. There are times I wished this could have been possible in the past. It will save, but not compile the code. So if you use the application it will only use the last successfully compiled version.

 

I thought that if there are errors it identifies this with a red 'x' so you can easily find them. It shows in the Problems pane so you can quickly see there, but not in the Applications pane, which is a little annoying.