Alex Ruben
How To Resolve the “Error Occurred While Unpacking” Issue with Fitgirl Repack (2025)
If you’ve ever tried to install a FitGirl repackage and got hit with that annoying “An error occurred while unpacking” message, you’re not the only one. It happens pretty often, especially with large or heavily compressed games. Basically, your setup can’t extract or verify some files properly, often due to missing DLLs, bad RAM, or virtual memory hiccups. Fixing this isn’t always straightforward, but usually a bit of tinkering with system files, settings, and dependencies will do the trick. Once sorted, the installation usually runs smoothly, and you don’t get those annoying errors anymore.
How to Fix ‘An Error Occurred While Unpacking’ During Repack Install
Method 1: Updating or replacing DLL files
This is kind of weird, but sometimes just replacing the isdone.dll and unarc.dll files in your system folder helps. These DLLs are kinda like the little workers that handle unpacking; if they’re corrupted, missing, or outdated, errors happen. You can get fresh copies from reputable sources like dllme.com for isdone.dll and dllme.com for unarc.dll. Just make sure you pick the latest versions, because of course Windows has to make everything more complicated.
Once downloaded, follow these steps:
- Right-click on
isdone.dlland Extract All (if it’s in a zip). - Same for
unarc.dll. Drag both extracted files to your desktop for ease. - Navigate to This PC, then Local Disk (C:), then Windows.
- Copy and paste the DLL files into System32. If prompted, choose Continue or Yes.
- For 64-bit Windows, also go to SysWOW64 and paste the DLL files there. This kind of dual placement is usually what fixes errors with unpacking DLL dependencies.
Note: Sometimes this just doesn’t take on the first try, and you need to restart or even re-copy. On some setups, it doesn’t hurt to replace the DLLs in both folders anyway, just to be safe.
Method 2: Install or Reinstall Visual C++ Redistributable Packages
This is often overlooked but super critical. Visual C++ redistributables contain runtime components needed by many programs, including unpackers. If these are missing or corrupted, errors crawl out of the woodwork. Head over to this link and download the ‘All-in-One’ package, which simplifies things. When installed, it can replace or repair any missing files.
Once downloaded, just run the installer, follow the prompts, and reboot if asked. Sometimes, you might need to reinstall the redistributable even if you think it’s fine — Windows has funny ways of saying “this is good enough” but actually isn’t.
Method 3: Adjust Virtual Memory Settings
This one tripped me up more than once — virtual memory, or paging file, is Windows’ way of using hard drive space as extra RAM. If it’s too low, large installers and unpackings fail or produce errors. Here’s how to set it up:
- Press Windows + R, type
sysdm.cpl, and hit Enter to open system properties. - Click on the Advanced tab, then hit Settings under Performance.
- Go to the Advanced tab in the new window, then click Change under Virtual memory.
- Uncheck Automatically manage paging file size for all drives.
- Choose your C drive, then select Custom size.
- Set the Initial size and Maximum size based on your RAM:
- 4 GB RAM: 2048 / 4096 MB
- 8 GB RAM: 4096 / 8192 MB
- 16 GB RAM: 8192 / 16384 MB
- 32 GB RAM: 16384 / 32768 MB
- 64 GB RAM: 32768 / 65536 MB
Method 4: Run the Installer as Administrator & Check Disk Space
Not sure why, but running the installer with full admin rights occasionally makes the difference. Right-click the setup file and choose Run as administrator. Also, verify you’ve got ample free space on your system drive — disks filling up trigger all sorts of weird errors, especially during unpacking. It’s a good idea to clear some space or move the install to a larger drive if possible.
Method 5: Reboot & Reinstall
Once you implement these fixes, reboot your system. Sometimes, the DLL files or registry settings need that refresh. After rebooting, try the install again. Which, surprisingly, often solves things — especially if the error was due to some transient file lock or memory clutter.
Extra Tips & Common Pitfalls
- Make sure your Windows is fully up to date — some unpacking issues are caused by outdated system files.
- Check if antivirus software is scanning or blocking the unpacker — sometimes it freaks out with large files.
- Ensure you run the installer as administrator — this can be a simple fix for permission-related errors.
- Keep an eye on disk space, especially on your system drive, where the unpacking happens.
Summary
- Replace DLL files if they’re corrupted or missing
- Install or repair Visual C++ redistributable packages
- Adjust virtual memory for better handling of large files
- Run setup as admin and make sure there’s enough disk space
- Reboot after changes and try again
Wrap-up
Aside from the typical “reboot and try again,” these steps really cover most scenarios that cause the “error while unpacking” message in FitGirl installs. Sometimes, it’s just a matter of fixing DLL issues, other times tweaking Windows settings or even updating dependencies. Hopefully, this saves someone hours of frustration. Most importantly, keep your Windows and drivers up to date, and double-check your system resources before starting a big install.