How do I get a storage to "forget" a backup with no rev?

This is the output for check -all -tabular :

       snap | rev |  | files | bytes | chunks | bytes | uniq | bytes | new | bytes |
       appdata_folder | all |  |       |       |      0 |     0 |    0 |     0 |     |       |

I’ve tried running prune -id appdata_folder -exhaustive but it’s still present afterwards.

Thanks!

You can delete the corresponding folder from the storage forum under snapshots folder