Python error related to data sources + synchronizing with QGIS

[Fabian Thiel]

2018-10-12T10:03:36     WARNING    Traceback (most recent call last):
              File "C:/Users/geo_fath/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\enmapboxplugin\enmapbox\gui\datasourcemanager.py", line 918, in onSync
              self.dataSourceManager.exportSourcesToQGISRegistry(showLayers=True)
              File "C:/Users/geo_fath/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\enmapboxplugin\enmapbox\gui\datasourcemanager.py", line 300, in exportSourcesToQGISRegistry
              if not l.isValid():
             RuntimeError: wrapped C/C++ object of type SpectralLibrary has been deleted