Greetings GreenDrag,

I'm sorry to hear that you have been experiencing this issue, and thank you for providing us with the thorough details and updates. The "Unable to complete version check" error you are referencing is often associated with interference of game data, or a connection issue. For errors such as these, we would recommend trying out the following troubleshooting, as it may help with alleviating the issue:

1. Please make sure all background applications have been disabled and/or closed to minimize game interference before attempting to log in. This includes any anti-virus programs you may have on the computer (such as Kaspersky, as you had mentioned).

2. If you haven't done so already, please be sure to adjust the following settings in "Internet Options" within the Control Panel:
- Under the "General" tab, please delete ALL browser history.
- Under the "Security" tab, please move the slider to the lowest possible settings or no higher than "Medium"
- Under the "Privacy" tab, click “Advanced” and select ‘Accept’ under both First Party and Third Party Cookies.
- Under the "Advanced" tab, please make sure that "Allow software to run or install even if signature is invalid" is CHECKED.
- Make sure that all SSL and TLS (EXCEPT SSL 3.0) are CHECKED. [SSL 3.0 should be UNCHECKED]
- Hit "Apply" to save the settings, and then "OK, to close the Internet Options menu.
- Right-Click on the FFXIV launcher icon and select "Properties"

Once these settings have been adjusted, hit "Apply", then "OK", and restart the PC after.

We hope these steps are helpful. Thank you for posting in the FINAL FANTASY XIV Technical Support Forums!