Migration Error in extJS

Hallo,

Shopware: 5.2.27
PHP: 5.6 und 7.0
Import von PrestaShop zu Shopware

bei mir funktioniert in verschiedenen Installationen das Plug-in Shop-Migration nicht. Ich bekomme folgenden fehler:

 

Uncaught TypeError: Cannot read property 'message' of undefined
    at i.failure (VM1786 Wizard&no-cache=1500549386+1+1:1270)
    at Object.callback (ext-all.js?201706221543:21)
    at i.afterAction (ext-all.js?201706221543:21)
    at i.onFailure (ext-all.js?201706221543:21)
    at Object.callback (ext-all.js?201706221543:21)
    at i.onComplete (ext-all.js?201706221543:21)
    at i.onStateChange (ext-all.js?201706221543:21)
    at XMLHttpRequest.<anonymous> (ext-all.js?201706221543:21)
failure @ VM1786 Wizard&no-cache=1500549386+1+1:1270
callback @ ext-all.js?201706221543:21
afterAction @ ext-all.js?201706221543:21
onFailure @ ext-all.js?201706221543:21
callback @ ext-all.js?201706221543:21
onComplete @ ext-all.js?201706221543:21
onStateChange @ ext-all.js?201706221543:21
(anonymous) @ ext-all.js?201706221543:21