While attempting to install a game or unpack software on your Windows 11 or Windows 10 computer, you might come across an error message stating: “An error occurred while unpacking: Does not match checksum.” This error often leaves users scratching their heads, especially when it’s accompanied by perplexing DLL (Dynamic Link Library) errors involving files like ISDone.dll and Unarc.dll, along with a seemingly random error code, such as “-12”, indicating a failed CRC (Cyclic Redundancy Check) check.
Although these error messages might seem complex, they’re manageable. In this article, we’ll explain these errors in simple terms and guide you on how to fix them.
What does “Does not match checksum” mean?
The “An error occurred while unpacking: Does not match checksum” error message may appear when you’re in the process of installing a software application or decompressing a compressed file, like a game installation package.
“Checksum” is a rather technical term, but think of it like a digital fingerprint of a file. Every file has its unique fingerprint or checksum. This is a way for your computer to check if the file is exactly how it should be, without any missing parts or changes.
When you see the error “Does not match checksum”, it means your computer compared the fingerprint of the file you’re trying to use with the fingerprint it expected to see. And they didn’t match. This mismatch can happen for a few reasons:
- The file might have gotten damaged or corrupted while downloading.
- Some parts of the file might be missing.
- There could be a glitch in the process of checking the file.
- The required components to install or unpack the game or software are missing, such as the Microsoft Visual C++ redistributable packages.
Imagine buying a puzzle and finding out a few pieces are missing. It’s similar to that. Your computer expected the full puzzle, but something was off.
Similar problem: Failed to start Denuvo driver. Error code: 2148204812
Solutions to fix the unpacking checksum mismatch error
Below are two straightforward steps to address and resolve the “An error occurred while unpacking: Does not match checksum” error when installing a game or software.
1. Verify the integrity of your installation files
The first and most crucial step in resolving the “Does not match checksum” error is to ensure that the setup and installation files are not corrupted or missing any parts. Here’s what you can try:
Re-download the installer
If you’ve encountered this error, the file you downloaded may be incomplete or corrupted. Begin by re-downloading the installer or compressed package from the official source. It’s essential to use a reliable internet connection and download the file from a trusted source to minimize the chances of corruption during the download.
Check file integrity with hash values
When you download certain files, especially bigger ones like games or software, the website might give you something called a “hash value.” This can be in formats like MD5 or SHA-256. These values act as digital fingerprints for the files, allowing you to check their integrity.
To make sure your downloaded file is in good shape:
- Compute the hash for your downloaded file using tools available online or software like “HashMyFiles”.
- Compare this hash with the one provided on the website.
- If they match, great! The file is as it should be. If not, there might be corruption, and you should download the file again.
2. Install Microsoft Visual C++ Redistributable
Sometimes, the “An error occurred while unpacking: Does not match checksum” issue isn’t with the file but with the tools and components your computer uses to unpack it. To address this, you can try installing the Microsoft Visual C++ 2013 Redistributable package. Here’s how:
- Download the Microsoft Visual C++ 2013 Redist package from Microsoft’s official website. Make sure to select the appropriate version (x86 or x64) based on your system.
- Double-click the downloaded file to start the installation process. Follow the on-screen instructions to complete the installation.
Note: For a more comprehensive solution that includes multiple versions of Visual C++ Redistributables, you can consider using the “VisualCppRedist_AIO_x86_x64.exe” package available on GitHub. This package is maintained by a trusted developer and includes a wide range of Visual C++ Redistributable versions. Here’s how to use it:
- Download the “VisualCppRedist_AIO_x86_x64.exe” package from GitHub.
- Run the downloaded file as an administrator. This package will install multiple Visual C++ Redistributable versions, ensuring that your system has the necessary components for software installations.
Linked issue: Microsoft Visual C++ Runtime Library Error Windows 10/11
Important tips and precautions
While the aforementioned solutions can often resolve the “Does not match checksum” error, it’s also crucial to follow some general precautions and be aware of some additional tips to ensure a smooth installation experience.
1. Ensure stable internet connection
A fluctuating internet connection can lead to incomplete or corrupted downloads. If possible, use a wired connection when downloading large files or ensure your Wi-Fi signal is strong and stable.
Related concern: Ethernet Internet Speed Capped at 100 Mbps (Fix)
2. Always download from trusted sources
Before hitting that download button, make sure you’re on a legitimate website or platform. Unofficial or shady sources not only risk giving you corrupted files but can also introduce malware or other threats to your system.
3. Check system requirements
Before installing any game or software, always check its system requirements. If your computer doesn’t meet the minimum criteria, it can lead to installation issues or performance problems.
Errors, especially during software installations, can be frustrating. They’re like roadblocks on a journey you’re excited about. The “Does not match checksum” error, while sounding technical, is just your computer’s way of saying something’s off with the file. While this error may initially seem daunting, it is often the result of file corruption or compatibility issues that can be resolved by either re-downloading the setup files or installing the required redistribution packages.