Fixed. No idea how.

Clean Steam install, all prior SupCom data deleted manually. No Antivirus software or other trash on the system. Trying to download maps produces this error message.

Logs:
Client Version: 2023.10.0
java.nio.file.NoSuchFileException: C:\Users\User\Documents\My Games\Gas Powered Games\Supreme Commander Forged Alliance\maps\gap of rohan.v0001
at java.base/sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:85)
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:103)
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:108)
at java.base/sun.nio.fs.WindowsFileSystemProvider.createDirectory(WindowsFileSystemProvider.java:521)
at java.base/java.nio.file.Files.createDirectory(Files.java:700)
at java.base/java.nio.file.Files.createAndCheckIsDirectory(Files.java:807)
at java.base/java.nio.file.Files.createDirectories(Files.java:793)
at com.faforever.commons.io.Unzipper.unzip(Unzipper.java:52)
at com.faforever.client.map.DownloadMapTask.call(DownloadMapTask.java:57)
at com.faforever.client.map.DownloadMapTask.call(DownloadMapTask.java:19)
at javafx.concurrent.Task$TaskCallable.call(Task.java:1399)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:833)

Thanks in advance.