I'm not sure if this is a feature request or a bug -- I'll let the mods decide.

 

When you start a docker and it requires a port allocation that is already in use, it simply doesn't start.  But.... there is no error message, no log entry, no evidence of why it failed.  It just doesn't start.  Would be great if Unraid issued a warning or at the minimum an error message informing you that the port was already in use.  

I came here to make the same request so I'll add my support to this. I do believe that it does indeed say that the port is already in use. Regardless, I think it would be nice if it checked and informed you before you save the template, maybe even prevent it from saving if the port is already in use. Currently, I expand docker allocations on the template page and can check that but it would be more convenient if it put a red asterisks or flashed or something if it was already in use. It's not usually a problem as most docker image creators check to make sure another CA docker isn't using the same port but it's a much bigger issue if you use the Docker Hub.