Hey there!
I'm glad that your server is working!
Let's not bother with the version.txt file. Let's do something which will provide some more accurate information.
Run the game (client), open console, type "status" without the quotes, hit enter and post the output here.
I am pretty sure that the client's version is newer than the server's version. And that's why you can't find the server in the servers browser and connect to it.