Console application for providing detailed error messages
Make a function that writes an error message (String) to the console, then exits with failure error code. But I'm not sure whether this would mess up your returns and overall control flow.

Other than that, I don't know. Yes, you can golf the string to "Unable to open X : " + x + ", it does not exist on the server", but all you're doing is making the error message harder to find when debugging later.

That said, "pretty" is pretty (Hah) abstract. As it is now, the code is perfectly readable, and it doesn't contain too much duplication. It doesn't contain any performance issues either. What you're seeing here is your code reaching the lowest Kolmogorov Complexity it can. 

But let's say, for the heck of it, you were to create some sort of function that takes a catalogName and returns either null or a Catalog object. In case of null, you have to call another function to get the error message. If you did that, you're just relocating the if statements. It also makes the design confusing. Basically, I don't think you can because you have to check and you have to report. In my opinion, you did that the prettiest way possible.