Been having this same problem myself lately when I decided to do a fresh install of TS2021 after the DTG update and was getting no where . The installer, which is now version 6.2 of course, kept coming back with “ERROR SEE LOG ” and it would generate the same message as seen above in the ATSOHLE log that appeared. I kept double checking my purchase ID ,my user name and password, all to no avail. The following is how I solved it and it turned out to be a simple fix.
Firstly create another user in Windows ie – ‘Window symbol’, ‘settings’, ‘accounts’, ‘Family and other users’ , ‘add someone else to this PC’, then click ‘I don’t have this person’s sign-in information’ then ‘add user without a Microsoft account’. Put any old user name in the box (it doesn’t matter), don’t put a password in and click ‘next’ . IMPORTANT – Make sure you change the attributes of your new account from ‘standard user’ to ‘administrator’
Sign out of your usual account and sign into your newly created one , log into this site ( Alan Thompson Simulation) and redownload the OHLE file from your purchase history then copy and paste it from your downloads folder onto on your desktop. Run as administrator, enter your user name, password and purchase number ( the 6 figure one not the licence key) also make sure the address of your railworks folder is in the required field and it should install no problems ( you will know because it will say ‘Done’) . You can then sign out again and log back into your usual account, bin the other account that you set up if you want and boot up TS2021 .You will find that you now have all the Alan Thompson OHLE installed .
Hope this is of some help