ReferenceError: clipboard is not defined

[UtmostCreator]

Description
Steps To Reproduce

1. open you external-caledar
2. make sure you have some events
3. create export
4. click on Copy to clipboard button

Actual Result: clicking on the Copy to clipboard button copies the url
Expected Result: throws the error ReferenceError: clipboard is not defined

TEXT:

humhub.log.js?v=1591265373:149 ERROR - humhub.modules.action: An unexpected error occurred. If this keeps happening, please contact a site administrator. ReferenceError: clipboard is not defined
    at jQuery.fn.init.<anonymous> (humhub.ui.additions.js?v=1591265373:139)
    at ActionBinding.handle (humhub.action.js?v=1596119240:550)
    at HTMLAnchorElement.<anonymous> (humhub.action.js?v=1596119240:802)
    at HTMLDocument.dispatch (jquery.js?v=1596124848:5429)
    at HTMLDocument.elemData.handle (jquery.js?v=1596124848:5233)

[buddh4]

Cannot recreate this,

• which HumHub version are you using?
• Did you try clearing the assets/cache?
• Are you running in production or debug mode
• Please check if there are any network errors in the network tab of your browser tool

[UtmostCreator]

Cannot recreate this,

• which HumHub version are you using?
  It is 1.6.2. Before (when I posted it), I was runnig 1.5.2
• Did you try clearing the assets/cache?
  Yeah, I have just did it, and after that I had a green pop-up (saving that is is succesfully completed)
• Are you running in production or debug mode
  I am running the debug mode -- defined('YII_ENV') or define('YII_ENV', 'dev');
• Please check if there are any network errors in the network tab of your browser tool
  I have got the next errors:
  

[UtmostCreator]

It works fine on HumHub develop branch (HumHub Community Edition Version: 1.7.0-dev)