There is something significantly wrong. At a minimum you should have a choice between ECMAScript and Rule DSL after “or choose the scripting language”.
Look in the logs for errors. If there are none all I can suggest is to file an issue on openhab-webuis.
If you want to choose JavaScript as your language (aka ECMAScript) you can start ;coding in that text area. But you should see a bunch of blocks to choose from on the left. So there is definitely something significantly wrong with your install.
