Isdonedll Unarcdll Error Code 6 Exclusive File
Alex tried the simplest thing first: increase virtual memory.
He right-clicked “This PC” → Properties → Advanced System Settings → Performance Settings → Advanced → Virtual Memory → changed it to custom size: Initial 8192 MB, Max 12288 MB. Restarted his PC.
No luck — still error -6.
Next, he checked his hard drive: it was formatted as FAT32. Big problem. FAT32 can’t handle single files over 4 GB, and Galactic Siege had several 6–8 GB archive files. He needed NTFS.
He backed up his data, then reformatted his game drive to NTFS. (Or, if he didn’t want to reformat, he could move the installer to an NTFS drive.)
Still no luck. Now he got suspicious.
He ran a memory test (Windows Memory Diagnostic). No RAM issues.
He ran CHKDSK /f on his drive — found and fixed some bad sectors.
Then, one more trick he found in a forum:
Force the installer to use less memory during unpacking.
He created a shortcut to setup.exe, right-clicked → Properties → Target → added this at the end:
setup.exe /nocrc
This told the installer to skip CRC checks (slightly risky, but often works if only a few bits are wrong).
Then, he also added:
setup.exe /VERYSILENT /SUPPRESSMSGBOXES /LANG=english /SP-
But that was overkill. What actually worked was simpler: run setup with low priority and increase page file. isdonedll unarcdll error code 6 exclusive
He opened Command Prompt as admin and typed:
start /low "C:\Games\Galactic_Siege\setup.exe"
Then, while the installer ran, he closed every other app — browser, Discord, Spotify — to free RAM.
At 72%, the installer paused. Alex held his breath.
85%… 94%… 100%.
Installation complete.
He launched the game. The main menu music played. He smiled.
Error code 6 tied to isdone.dll or unarc.dll typically appears when installing compressed games or large software packages. It means the installer/unpacker failed to extract or verify compressed data — generally due to corrupted archives, bad memory, disk I/O problems, or missing/corrupt system libraries.
Disable Antivirus/Firewall: The most common culprit is heuristic scanning. Windows Defender or third-party AV solutions often flag the high-volume file operations of repacks as suspicious behavior.
Clean Boot State: Ensure no background processes are interfering with file handles.
Run as Administrator: Right-click the setup executable and select "Run as administrator." This grants the installer elevated privileges required to modify system directories and claim exclusive file handles.
Check Disk Integrity:
Run chkdsk /f /r in an elevated Command Prompt to ensure the destination drive does not have bad sectors preventing the write operation. Verify integrity
Final Recommendation: If the error persists despite these measures, the source archive itself is likely corrupted. Re-downloading the installer from a different source or verifying the hash values (MD5/SHA-1) against the uploader's provided values is necessary.
Dealing with ISDone.dll error code 6 is a common headache, especially when installing large, highly compressed games or repacks. This specific code typically points to an issue where the installer is unable to read data from the source or write it properly to the disk. Microsoft Learn
Here is a breakdown of why this happens and how you can actually fix it. What Does Error Code 6 Mean?
While other codes might mean your RAM is failing (code 7 or 12), Error Code 6
usually indicates a "read error" or "file mismatch". This means the data the installer is trying to unpack is either physically unreadable (bad drive sector), being blocked (antivirus), or the path to the files is too complex for the installer to handle. Microsoft Learn The Best Fixes to Try First Check for Non-Latin Characters
: This is a frequent, "hidden" cause. If your Windows username or the folder you are installing to contains characters like ö, é, or Cyrillic letters , the installer often fails. : Ensure the installation path is simple, like C:\Games\MyGame Disable Real-Time Antivirus
: Antivirus programs often flag the heavy decompression activity of as suspicious, stopping the process midway. : Turn off Windows Defender
or your third-party antivirus temporarily during the install. Increase Virtual Memory (Page File)
: Even if you have 16GB of RAM, these installers need a "safety net" on your hard drive to handle massive data chunks. System Properties Performance Settings Virtual Memory and set a manual size (e.g., 8000MB to 16000MB). Run as Administrator & Safe Mode Run as Administrator
: Windows permissions sometimes block the installer from writing to the : Right-click the installer and select Run as Administrator . If that fails, try installing while booted in Advanced Solutions for Newer Hardware If you have a high-end, modern processor (like Intel 13th/14th Gen
), the installer might be crashing because it's trying to use too many cores at once. Limit Processor State : Set your Windows Power Plan to "Balanced" and change the Maximum Processor State in Advanced Power Options. Limit Cores
to temporarily limit your active cores to 6 or 8 during the installation process. Still Stuck?
If none of the above work, the installer files themselves might be corrupted from the start. Try re-downloading the game with your antivirus off, or use a tool like CrystalDiskInfo
to check if your hard drive has "bad sectors" that are preventing the data from being written. How to fix isdone, unarc.dll error, code 1, 6, 7, 12, 14 #2
“isdonedll unarcdll error code 6 exclusive”
Error code 6 can trigger when Windows runs out of exclusive contiguous memory space.