Hello , so you said that you can't open with a "particular verilog file" , and if the problem it's not about the license, than perhaps the file is opened in read-only mode, because you don't have write permissions or maybe the file have +x(executive permissions) on it. I've encountered the same problem in Virtuoso Layout, because the file had executive permission. And when I was opening it, a message appeared " Opening in read mode "(or something like that), so what did I do, I removed the executive permission from that file, and all worked fine.... Maybe this is your cause here too. So be sure of the file's permissions.
I hope that you'll resolve this problem.
Have a nice day !