Save SHSH blobs within 48 hours of a new iOS release for best results. Don’t wait.
Apple only allows you to install iOS versions they are currently "signing". how to fix error unable to request shsh on 3utools when new
This usually happens when Apple stops signing a firmware version, but if you are seeing this error when a version is new and still signed, it can be incredibly confusing. Here is a review of why this error occurs and a step-by-step guide on how to fix it. Save SHSH blobs within 48 hours of a
Make sure you're following the correct process for requesting SHSH blobs: how to fix error unable to request shsh on 3utools when new