Teamviewer 14.1.3399, Ubuntu 14.04, GUI won't start

The tray icon does exist, but the GUI won't load. I also tried the suggested command:

sudo apt-get install teamviewer=14.0.14470

in order to downgrade the version. The downgrade completed successfully, but the issue remains. I get the following errors in the log:

2019/01/02 10:47:43.100  2896 **Please do not post TeamViewer IDs**32928 GX0!! QML load error: qrc:/ui/Options/OptionsDialog.qml:11:1: Type TVWindow unavailable
2019/01/02 10:47:43.100  2896 **Please do not post TeamViewer IDs**32928 GX0!! QML load error: qrc:/ui/QuickCommon/TVWindow.qml:14:2: Type WindowSheetContainer unavailable
2019/01/02 10:47:43.100  2896 **Please do not post TeamViewer IDs**32928 GX0!! QML load error: qrc:/ui/QuickCommon/WindowSheetContainer.qml:123:4: Type TVContent unavailable
2019/01/02 10:47:43.100  2896 **Please do not post TeamViewer IDs**32928 GX0!! QML load error: qrc:/ui/QuickCommon/Style/TVContent.qml:31:2: Type TVSplitter unavailable
2019/01/02 10:47:43.100  2896 **Please do not post TeamViewer IDs**32928 GX0!! QML load error: qrc:/ui/QuickCommon/Style/TVSplitter.qml:42:9: Cannot assign to non-existent property "bottomMargin"

The 13.xxxx version seems to work OK.

Any suggestions are welcome.