UseExistingDatabase=1 needs an ApplicationKey

No key was found in Install.ini, the key file, the legacy folder, or Config. Restore the key from the -getconfig backup and set ApplicationKey=.

initconfig or validateconfig reports a key mismatch

The Config folder may be stale after uninstall. For existing databases, set the correct key and let the installer remove the stale Config folder. For new databases, cleanup is automatic.

ApplicationKey does not match existing database

The key or database selection is incorrect. Use the key from the original installation.

Warning: SYS_APP_KEY_CHECK could not be verified

This warning is common for upgraded databases. Continue only if the key is trusted; the installer refreshes the check value at the end.

Database already exists (new-database install)

Use existing-database mode, or drop or rename the databases if it is safe to do so.

Eempty Config folder after upgrading to new folder.

Make sure the old program folder is accessible. If needed, copy Config manually or set LegacyProgramFolder=.

InitData / Front Office initialization fails

Review the install log. In 11.2, failures include sqlcmd output. Verify SQL permissions and available disk space.

Dapi password still ChangeMe in connectionStrings

This is a known limitation. Configure Dapi after installation.

Second node initconfig fails (load balanced)

Use the same ApplicationKey hex value. Do not copy .enc files between servers.