I updated Max 2021 with MaxToA 18.104.22.168 without any problem. However MaxToA for Max 2020 did not install properly in Max 2020 on my machine. When I started Max 2020 after the maxtoA 22.214.171.124 install, I received an error message that "C:\ProgramData\autodeskapplication..........MaxtoA.dlr failed to initialize. Error Code 126 The specified Module could not be found." After dismissing the error code dialog box I go the same message for MaxtoA_Menu.gup. And of course, While max eventually started up, Arnold was not an available render option. However, when I checked the path for both .MaxtoA.dlr and MaxtoA_Menu.gup , both files were in the directory they should be in. I tried rebooting my machine, but got the same result.
I installed the previous version of MaxtoA 126.96.36.199 in Max 2020 which works fine. This may be a an installation bug?