If you are using a FitGirl repack specifically, look for the checkbox at the start of the installer that says Checking this box slows down the installation but is the single most effective way to prevent ISArcExtract.dll crashes on 64-bit systems.
Lack of updated Visual C++ Redistributables. How to Fix ISArcExtract.dll Errors 1. The "Quick Fix": Disable Antivirus isarcextractdll 64 bit
Set Initial and Maximum size to (e.g., if you have 8GB, set it to 12288 MB). 3. Update Visual C++ Redistributables If you are using a FitGirl repack specifically,
Type in your search bar. Go to the Advanced tab > Change (under Virtual Memory). Uncheck "Automatically manage..." Select your C: drive, click Custom Size . The "Quick Fix": Disable Antivirus Set Initial and
When your computer fails to unpack these files into your RAM or onto your hard drive, the installer "panics" and throws the ISArcExtract error. Common Causes for the Error
Decompressing large files is extremely RAM-intensive. If your memory has a tiny defect, it shows up here.
Downloading individual DLL files from "DLL fixer" websites is a security risk and rarely works. The problem isn't usually that the file is missing; it’s that the process it governs is being interrupted by your hardware or OS. Pro-Tip for Repack Users