Answer
This is often related to Windows 8.3 short-filename support being disabled on the install drive, which breaks path resolution for tools that rely on short-name paths internally. Checklist to work through: assign the server a fixed IP address and add it (with hostname) to C:\Windows\System32\drivers\etc\hosts; confirm the install drive supports DOS 8.3 short names (check with dir /x <DRIVE_LETTER> — if entries show no short-name column, they're disabled); if disabled, enable them with fsutil 8dot3name set <DRIVE_LETTER> 0, though note this only affects newly created files/folders going forward, so for an existing IFS_HOME you'll need to stop all its processes/services, rename the IFS_HOME folder temporarily, then rename it back to force Windows to regenerate proper 8.3 short names for it; also check whether the ifs user's password contains characters like #, =, or ! — these are known to cause similar issues and should be changed via <IFS_HOME>\instance\<INSTANCE_NAME>\bin\change_mws_password.cmd if present.