I don't think it will work on Elgg 2.3 without a thorough code upgrade. The latest version available (1.7) was released for Elgg 1.8 and much has changed since then (first with Elgg 1.9 and then again - a bit less - with Elgg 2.0). Maybe someone will respond who has done the code upgrade but not released a working version. But to be honest I wouldn't have too high hopes. If you need an auction plugin urgently, it might be necessary to hire a developer to do the work. You could also take a look at the plugins available at https://github.com/hypeJunction?tab=repositories. If I remember correctly there were some shopping plugins available there. But I can't say for sure (and not by own experience) if they are fully working or even providing full functionality as they are or are rather a kind of basis that you would have to extend/customize to get a full working solution. Problem with these plugins (like with the auction plugin) is that the developer of the hype* plugin has stopped working further on these plugins (they work on Elgg 2 but in future releases of Elgg like version 3 already they would likely require some updates).

I think the problem is that the code of the Time Theme Pro plugin (probably based on the Time Theme from the same developer) wasn't completely and correctly updated to take into account the changes necessary to work on Elgg 2. One thing that probably causes the error is that Elgg JS code is no longer loaded in the page header but loaded asyncronously as AMD modules. Plugins should do it the same way. And in case a plugin relies on any Elgg core JS it will cause errors as the loading order is not necessarily the same if you don't define dependencies correctly.

Maybe someone can suggest a working alternative theme to you (unfortunately I can't as I have written my own theme for personal use based on the default Aalborg theme and never really tried any others on Elgg 2).

Or you might have to think about hiring a developer if you need a theme with specific features and a look you like but don't find one you like.

ok thank you man

@RvR where's the docs that explain how to make a plugin please ? 

http://learn.elgg.org/en/stable/tutorials/hello_world.html