This error also may be caused by a conflict with the SSL libraries (libcrypto-1_1-x64.dll and libssl-1_1-x64.dll).
Usually these are loaded from the path where is running Update Manager (C:\Program Files\Itoo Software\Common).
But if there is some route in the PATH environment variable with the same libraries, it would cause the conflict.
Please try running Update Manager using the attached BAT file, and see if there is some difference.