If you have a confirmed safe copy of xwis.dll but Windows isn’t recognizing it, register it manually:
If you are determined to play specifically on the XWIS server infrastructure, you should look for the official XWIS patches. These are usually found on older fan forums or the XWIS website archives. xwis.dll file download
Once you’ve resolved the issue, take these steps to ensure it never reappears: If you have a confirmed safe copy of xwis