Trouble sharing wifi connection (ad-hoc network)

it is possible to have wired internet connection and create ad-hoc wifi connection on ubuntu. I have done it few times on my Linux Mint and Ubuntu.

Unfortunately, there is an issue with it on Zorin. Normally it's a matter of creating new network with "ad-hoc" and "shared to other computers" options and connecting to it. Zorrin simply doesn't broadcast network.

Can you check on your system if it works for you ? You need to be wire-connected and create wifi network as per this how to: http://tumutanzi.com/archives/8195

Or is it possible that it's a problem with my HTC ?

You need to search in google for instructions on how to set up your specific HTC model so as to make it able to connect to ad-hoc networks.