Metadata editor: Python error when tyring to save edits

[Fabian Thiel]

An error has occurred while executing Python code: 

AssertionError 
Traceback (most recent call last):
  File "C:\Users\geo_fath\AppData\Roaming\QGIS\QGIS3\profiles\default\python\plugins\enmapboxplugin\enmapbox\coreapps\metadataeditorapp\metadataeditor.py", line 974, in saveChanges
    self.mMetadataModel.writeMetadata()
  File "C:\Users\geo_fath\AppData\Roaming\QGIS\QGIS3\profiles\default\python\plugins\enmapboxplugin\enmapbox\coreapps\metadataeditorapp\metadataeditor.py", line 497, in writeMetadata
    differences = self.differences(self)
  File "C:\Users\geo_fath\AppData\Roaming\QGIS\QGIS3\profiles\default\python\plugins\enmapboxplugin\enmapbox\coreapps\metadataeditorapp\metadataeditor.py", line 277, in differences
    assert isinstance(rootNode, TreeNode)
AssertionError

[Fabian Thiel]

AND

the ... -Button is not working. I suppose it should open a File selection/Open data source dialog?