An error occurred while unpacking: Does not match checksum

Published by Nyau Wai Hoe - Updated on

When you’re setting up a game or some software on your Windows 11 or Windows 10 computer, you might bump into a message saying: “An error occurred while unpacking: Does not match checksum.” Plus, you might see some weird errors about DLL files like ISDone.dll and Unarc.dll, along with an error code like “-12” that talks about a CRC (Cyclic Redundancy Check) check failing.

These messages can be a bit confusing, but they’re not too tough to handle. We’re here to break them down in easy terms and help you fix them.

An error occurred while unpacking Does not match checksum

What does “Does not match checksum” mean?

The “An error occurred while unpacking: Does not match checksum” message pops up when you’re installing software or opening a compressed file, like when you’re getting a game ready to play.

Think of “Checksum” as a digital fingerprint for files. Each file has its unique mark. Your computer uses this to check if a file is complete and unchanged.

Example of file hash value for checksum

Seeing the error “Does not match checksum” means the file’s fingerprint didn’t match what was expected. This could be because:

  1. The file got damaged or corrupted while downloading.
  2. Parts of the file are missing.
  3. There was a glitch in checking the file.
  4. Some needed components for installing or opening the game or software are missing, like the Microsoft Visual C++ redistributable packages.

It’s like getting a puzzle and finding out pieces are missing. Your computer expected the whole thing, but something wasn’t right.

Similar problem: Failed to start Denuvo driver. Error code: 2148204812

Solutions to fix the unpacking checksum mismatch error

Here are a couple of simple steps to sort out the “An error occurred while unpacking: Does not match checksum” error when setting up a game or software.

1. Verify the integrity of your installation files

The first big step to solve the “Does not match checksum” error is to make sure the setup and installation files are all good, not corrupted or missing bits. Here’s what to do:

Re-download the installer

If this error comes up, the file you got might be broken or not complete. Start over by downloading the installer or package again from the official site. Make sure your internet is good and the source is trustworthy to avoid file corruption during the download.

ISDone.dll Unarc.dll An error occurred while unpacking

Check file integrity with hash values

When downloading big files like games or software, the site might give you a “hash value.” This is like a digital fingerprint. You can use it to check if your file is okay.

Also see: How to Verify MD5 or SHA256 Checksum in Windows 11

To check your file:

  • Use tools online or software like “HashMyFiles” to find the hash of your file.
  • Compare it with the hash on the website.
  • If they’re the same, you’re good! If not, the file might be corrupted, so try downloading it again.

Check file integrity with hash values

2. Install Microsoft Visual C++ Redistributable

Sometimes, the problem isn’t the file but what your computer needs to open it. Try installing the Microsoft Visual C++ 2013 Redistributable package. Here’s how:

  • Get the Microsoft Visual C++ 2013 Redist package from Microsoft’s official website. Pick the right version (x86 or x64) for your system.
  • Double-click the file you downloaded and follow the steps to install it.

Microsoft Visual C++ 2013 Redistributable

Note: For more Visual C++ versions, consider the “VisualCppRedist_AIO_x86_x64.exe” package from GitHub. It’s trusted and includes many Visual C++ versions. Here’s how to use it:

  • Download “VisualCppRedist_AIO_x86_x64.exe” from GitHub.
  • Run it as an administrator. It installs many Visual C++ versions, making sure your system has what it needs for software installations.

Linked issue: Microsoft Visual C++ Runtime Library Error Windows 10/11

Important tips and precautions

While the steps above often fix the “Does not match checksum” error, here are some general tips and things to remember for a smooth setup:

1. Ensure stable internet connection

A bad internet connection can mess up downloads. Try a wired connection or make sure your Wi-Fi is strong when getting big files.

Related concern: Ethernet Internet Speed Capped at 100 Mbps (Fix)

Internet Connection Speed Test

2. Always download from trusted sources

Be sure you’re downloading from a safe and official site. This keeps you from getting bad files and protects you from malware.

3. Check system requirements

Always look at the game or software’s requirements before installing. If your computer doesn’t fit the bill, you might run into trouble during setup or while using it.

Useful tip: Check PC Hardware Manufacturer & Model via WMIC in CMD

Final thoughts

Getting errors when installing software is annoying, like hitting a roadblock when you’re excited to start something. The “Does not match checksum” error might sound technical, but it’s just your computer’s way of telling you something’s wrong with the file. These issues usually come from corrupted files or missing components but can often be fixed by re-downloading the setup files or installing the needed packages.

Nyau Wai Hoe
Nyau Wai Hoe is the Founder and Chief Editor of With a degree in software engineering and over 12 years of experience in the tech support industry, Nyau has established himself as an expert in the field, with a primary focus on the Microsoft Windows operating system. As a tech enthusiast, he loves exploring new technologies and leveraging them to solve real-life problems.

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