What are you using to create the installer? (Windows, macOS, or Linux?)
Step 2: Converting Official Files into Standard Image Formats (.DMG / .ISO) Using macOS High Sierra in 2025 top download macos high sierra 10135 image file rdr
If you need macOS High Sierra, avoid third-party proprietary clones and stick to official methods: Using macOS High Sierra in 2025 What are you using to create the installer
If you downloaded an image from a non-Apple source, you MUST verify its integrity. This python script connects directly to Apple's Catalog
If you are locked out of the App Store because you are using a newer Mac operating system or a PC, you can use the open-source community tool . This python script connects directly to Apple's Catalog Server URL to download complete, pristine installer packages. Navigate to the gibMacOS GitHub Repository. Download and extract the ZIP file.
Some RDR sources:
Click or "Download" to download the Install macOS High Sierra.app file straight into your Applications directory.