Firstly, I apologise sincerely for the error.
I have a workaround that should restore the content identifier:
* Browse into your TVH system (
http://{YOUR_TVH_IP_ADDRESS}:9981).
* Navigate to the tab 'Configuration' -> 'Channel / EPG' -> 'EPG Grabber'.
* Ensure that you set your 'View Level' (top right) to 'Expert'.
* The 'Over-the-air Genre Translation:' setting should appear.
* Enter '0=0' (no quotes) into this field and then press the 'Save' button.
* Press the 'Trigger OTA EPG Grabber'.
* Your EPG should be repopulated with the content identifier.
This workaround 'should' do no damage. It simply tells the EIT section to translate identifier 0 to identifier 0. As the identifier is the same and identifier 0 is 'Undefined' anyway, it should be ignored.
I have already identified the source of this problem and I will work to rectify the situation.
Naturally, I tested this on my system prior to releasing the change and it was working fine. However, I was able to reproduce this error on my system after first using a completely new/clean installation that has never had this modification and then upgrading.