Unexpected Application Error!

Cannot read properties of undefined (reading 'toString')

TypeError: Cannot read properties of undefined (reading 'toString')
    at c (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:88:197587)
    at Uj (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:88:197626)
    at Ph (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:42:17009)
    at R1 (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:44:43963)
    at C1 (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:44:39727)
    at tE (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:44:39655)
    at iu (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:44:39508)
    at bf (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:44:35875)
    at b1 (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:44:34826)
    at M (https://aks-components.messe-muenchen.de/gbw-calendar/prod/dist/assets/index.js:29:1585)