Solution: This is a common Gatekeeper message for unsigned builds. Run in Terminal:
sudo xattr -rd com.apple.quarantine /Applications/QGIS.app
Solution: You cannot have two different major versions of QGIS installed via the same installer type. You can, however, keep QGIS 3.28 (LTR) and QGIS 3.26 side-by-side if you install one via OSGeo4W and the other via Standalone. Or, uninstall the newer version first. qgis 3.26 download
After completing your QGIS 3.26 download and installation, verify that you have the correct version: Solution: This is a common Gatekeeper message for
If you see a newer version (like 3.28 or 3.34), you accidentally downloaded the latest release instead of the archived 3.26 release. If you see a newer version (like 3
C:\Program Files\QGIS 3.26).You can install QGIS 3.26 alongside other versions of QGIS (such as the LTR).