Undefined tone name in tone system leads to crash

[keinstein]

Try

Ton a' = 440 "Hz"
Intervall
    Oktave = 2:1
    Quinte = 3:2
    

Ton 
    ais   = dis  + Quinte
    dis   = gis  + Quinte - Oktave
    gis   = cis  + Quinte
    cis   = fis  + Quinte - Oktave
    fis   = h    + Quinte - Oktave
    h     = e    + Quinte
    e     = a    + Quinte - Oktave
    a     = 440 "Hz"
    d     = a    - Quinte
    g     = d    - Quinte + Oktave
    c     = g    - Quinte
    f     = c    - Quinte + Oktave
    b     = f    - Quinte + Oktave
    es    = b    - Quinte
    as    = es   - Quinte + Oktave
    des   = as   - Quinte
    ges   = des  - Quinte + Oktave
    ces   = ges  - Quinte
    fes   = ces  - Quinte + Oktave
    bes   = fes  - Quinte + Oktave
    eses  = bes  - Quinte
    asas  = eses - Quinte + Oktave
    deses = asas - Quinte
    
Tonsystem
    Testtonleiter = 60 [ c, des, cis, d, es, dis, e, f, ges, fis, g, as, gis, a, b, ais, h] Oktave 
    Rast     = 60 [ c     ,      ,     d,      ,   fes, geses,      ,     g,      ,     a,      ,   ces] Oktave
    Nihavend = 60 [ c     ,      ,     d,    es,      , geses,      ,     g,    as,      ,     b,      ] Oktave
    Ussak "Uşşak"    = 60 [ c     ,      ,  eses,    es,      , geses,      ,     g,    as,      ,     b,      ] Oktave
    Huseyni "Hüseynî"  = 60 [ c     ,      ,  eses,    es,      , geses,      ,     g,      ,   bes,     b,      ] Oktave
    Hicaz    = 60 [ c     ,   des,      ,      ,   fes, geses,      ,     g,      ,   bes,     b,      ] Oktave
    Huzzam "Hüzzam"   = 60 [ deses ,   des,      ,    es,     e,      ,      ,  asas,    as,      ,     b,      ] Oktave
    
Logik 
    Test Taste T = Testtonleiter []
    Makalam Taste L = [
        Taste R -> Rast
        Taste N -> Nihavend
        Taste K -> Ussak "Uşşak"
        Taste Y -> Huseyni "Hüseynî"
        Taste H -> Hicaz
        Taste Z -> Huzzam "Hüzzam"
    ]