Which browser is currently set as default browser?
(Settings -> Apps -> Default Apps)
Do you by any chance have (Oracle) Java Runtime Environment installed on your system?
Below Settings -> Privacy -> Applications you can check if and what apps are allowed to access your account on your system. Could you check if access to account details is allowed for apps on your device. Although it’s probably not related to this problem.
Could you also check Add/Remove programs and post a screenshot of all installed VC++ libs.
Last but not least I managed to simulate this error using loading MSHTA with some defect javascript. On that I based my advise to run an additional scan.
You did completely reinstall the game from Steam already, so it would not have use to check the integrity of the installed binaries.
This also might be some kind of code page or wrong charset issue. Something goes wrong interpreting the embedded javascript. So your problem could be related to missing VC++ libs too.