Getting Error: Ext.fly(...).addCls is not a function when compiling with sencha cmd

[JSassy]

Hi,

I have installed Sencha Cmd v6.6.0.13 and use it to compile all my sources to get one single file.
ExtJS Version 4.1.3.

This command executed in the windows-cmd works fine:
sencha compile --classpath="D:\Libraries\ext-4.1.3\src,lib\extjs\ux,lib/extrequires.js,lib\Osiris" -option debug:false concat -compress all.js

Since a few days I am trying to use this within ant:

<x-sencha-command>
    compile
        --classpath=D:\Libraries\ext-4.1.3\ext-all-dev.js,${web}\core\lib\extjs\ux,${web}\core\lib\extrequires.js,${web}\core\lib\Osiris
        --options=debug:true
    concatenate
        --append=true
        --output-file=${web}\core\all.js
</x-sencha-command>

But when I start the application using the file generated via ant, I am getting the following error:

Uncaught TypeError: Ext.fly(...).addCls is not a function
    at initExtCss (all.js:6866)
    at all.js:6736
    at constructor.fire (all.js:6703)
    at constructor.readyEvent.fire (all.js:6875) 
   at fireReadyEvent (all.js:6921)
    at all.js:84807

Any idea, what's wrong? Thank you.

[Forum_Adm]

Thank you so much for your post. I apologize for the delay. I have shared this with the support staff to look into at their earliest convenience. Your patience is greatly appreciated! We do suggest using the support portal when you need assistance with a capability of a Sencha product, you have identified a situation where a products behavior is inconsistent with the product documentation and might indicate a software bug, or when the communication between you and Sencha needs to be private.

Thanks again,

Michele