IzoT CT is a 32-bit Application which runs on 32-bit or 64-bit Windows. Izot CT requires 32-bit Visio and will not work with 64-bit Visio. If your PC is using 64-bit Office, you will need to un-install and re-install the 32-bit edition.
If you have Office 365, these are instructions from Microsoft:
Download and install or reinstall Microsoft 365 or Office 2021 on a PC or Mac
To change from a 32-bit version to a 64-bit version or vice versa, you need to uninstall Office first (including any stand-alone Office apps you have such as Project of Visio). Once the uninstall is complete, sign in again to www.office.com and select Other install options, choose the language and version you want (32-bit), and then select Install.
To change from a 32-bit version to a 64-bit version or vice versa, you need to uninstall Office first (including any stand-alone Office apps you have such as Project of Visio). Once the uninstall is complete, sign in again to www.office.com and select Other install options, choose the language and version you want (32-bit), and then select Install.
As an alternative, some customer use a Virtual Machine for IzoT CT.