Hi @Scofus
Preinstalled apps like the gallery should not be uninstalled.
To fix this, you have to reinstall the whole system from a computer using the UBports installer.
As @MrT10001 you'd want to NOT select the "wipe data" box if you want to keep your data.
Alternatively, you can also switch to another channel (RC for example) and then switch back to the current one (Stable I presume).