UndefVarError: MaggotUBA not defined

On editing an outline file and saving some manually-assigned labels to file, LarvaTagger.jl crashes with the following stack trace:

┌ Warning: error in websocket handler!                                                                                           
└ @ JSServe /usr/local/share/julia/packages/JSServe/kIK9q/src/http.jl:84                                                         
UndefVarError: `MaggotUBA` not defined                                                                                           
Stacktrace:                                                                                                                      
  [1] explicit_editions_needed(controller::LarvaTagger.ControllerHub, editiontag::String)                                        
    @ LarvaTagger /app/src/files.jl:416                                                                                          
  [2] savetofile(controller::LarvaTagger.ControllerHub, file::String; datafile::Nothing, merge::Bool)                            
    @ LarvaTagger /app/src/files.jl:278                                                                                          
  [3] savetofile                                                                                                                 
    @ /app/src/files.jl:244 [inlined]                                                                                            
  [4] (::LarvaTagger.var"#183#185"{LarvaTagger.ControllerHub, LarvaTagger.ControllerHub})(file::String)                                                                                                                                                       
    @ LarvaTagger /app/src/files.jl:472
  ...