Boot Camp not recognizing Windows 10 ISO file on Big Sir

I am trying to install Windows 10 on a 2017 Macbook Pro 15 running the latest version of BIG SIR (Dec. 8, 2020) using boot camp. After launching boot camp and choosing the windows partition size, I get an error that says the Windows 10 ISO is not recognized. This is a freshly downloaded ISO from Microsoft website and placed on my desktop. Its the only file available from Microsoft and I'm selecting the 64-Bit version. I've tried numerous times and same error message. Any help would be greatly appreciated.

thanks