If your worker levels up, his xp will be always 0, even if he was at 99.99% before the work finishes, any excess xp apart from what needed for the next level is lost.
Install the Black Desert Launcher if the game doesn't start.
The launcher will appear if it's installed.
If it doesn't, try to run your downloaded launcher.
1 Run BlackDesert_Installer_NAEU.exe to install the Black Desert launcher.
2 Start the game once installation is complete.
If your worker levels up, his xp will be always 0, even if he was at 99.99% before the work finishes, any excess xp apart from what needed for the next level is lost.