Do the following:
1. Un-install the game. Reboot your PC.
2. Install the game (make sure it is installed in the root directory or anywhere else except the Program Files folder). Go to the game folder, right-click Ragexe & Ragnarok.exe separately, choose Properties. In the pop-out window, click on the Compatibility tab, check the box that says "Run this program as an administrator" followed by Apply & Ok.
3. Download the following folder: https://drive.google...REhXYjFncEtYdlU which contains almost all the patch files released since February until 21st of September 2017.
4. Scan it with your AV of choice, extract the contents to the game folder.
5. Run the desktop short-cut or Ragnarok.exe inside the game folder.
6. Once it has successfully patched, close the patcher, Re-open it again to confirm it isn't downloading and unpacking the patch files again. Finally log into the game and see if you still have error messages popping up.
If the issue is resolved, delete the patch files you extracted from archive in the previous step from the game folder.
And if this doesn't solve your issue, I do hope someone else can make it work.