This error may arise with the network-licensed variant of ReFH2, versions 4.1.8985 and older.
If you see this message when ReFH2 starts, please download and install the latest version (network-licensed edition). It is not necessary to uninstall your current version first.
If you see this message and are using the standalone-licensed variant, or are using versions 4.2.9348 or newer, please contact us for help.