If you see block / icons where text should be, then the unit requires a reboot or updating.
The blocks are due to language text is missing or corrupt xml
First reboot screen.
>> More (3 dots)
>> Reboot
If this does not fix the issue, then the screen will need updating.
You will require a Laptop and Micro USB lead (to plug into the side of the Touch screen Monitor)
Download Quick update tool
http://downloads.orcomm.co.uk/#Downloads%2FSoftware%2FTools%2FUSB%20Upgrade%20Tool
Download latest firmware (Orcomm toolbox compatible)
http://downloads.orcomm.co.uk/#Downloads%2FFirmware%2FSmart%20Screens%2FORC-4T
Open the Upgrade tool and select the Firmware file.
Upload to screen, and wait approximately 1 minute for screen to update. (note it may reboot few times checking files are installed.