What issue arises if you backup Qlik Sense without stopping services?

Backing up Qlik Sense without stopping services can lead to the issue where apps and the repository become out of sync. This happens because Qlik Sense operations, such as data reloads, user interactions, and other ongoing processes, are actively writing to the repository and the app files. When a backup is taken while these processes are ongoing, it captures the state of the applications and the repository at that precise moment, which may not represent a consistent view.

As a result, any changes made to the apps during the backup process might not be included, or the backup might reflect an intermediate state that doesn't fully respect the integrity of the data. This can create discrepancies between the backed-up files and the actual state of the applications and repositories once the services are resumed, leading to potential data inconsistencies and challenges when restoring from that backup.

In contrast, while other options suggest possible issues such as a failed backup or longer backup times, these are less critical than operational inconsistencies which pose a significant risk to data integrity and application functionality when restoring from a backup taken without proper service management.