Errors are generated when performing an offline installation of Qt 5.15.15 Desktop gcc 64-bit (without Qt Creator or any other components) to CentOS/RHEL 7 hosts, which is a supported configuration. These errors result from the installer calling an sdktool executable that has been built against Qt 6, which is not supported. Choosing to ignore these errors is a work-around that allows the installation to complete successfully.

A similar issue has been reported and already fixed in the online installer:

    https://bugreports.qt.io/browse/QTCREATORBUG-27508 (duplicate of below, but very clear description of behavior)

    https://bugreports.qt.io/browse/QTCREATORBUG-26811

These errors no longer occur in the online installer (IFW 4.6.1). However, they remain in the offline installers (currently IFW 4.6.0).