Published by: Tech Game Support Reading Time: 4 minutes

Or, even worse:

Here is the ultimate guide to killing these errors for good. These aren't viruses. unarc.dll is a library used by archivers (like WinRAR/7-Zip) to decompress data. The isdone.dll error is simply the dialogue box telling you the decompression failed.

Did this work for you? Let us know in the comments below. If you got a specific error code (like -1, -6, or -14), mention it—we have specific fixes for those too.

Turn off antivirus > Run as Admin > Limit RAM usage (2GB) > Use an NTFS drive.

If you are seeing isdone.dll or unarc.dll errors during the GTA V setup (usually from a FitGirl repack or a large ISO file), These errors are almost always caused by system resource conflicts.

There is nothing more frustrating than waiting hours for Grand Theft Auto V to download, only to be slapped with a cryptic error box halfway through the installation. You step away for a snack, come back, and see it: