SUMMARY 
Since the last kde update, when a .xmi file is created with umbrello, it's impossible to open it with umbrello, an error message is displayed.


STEPS TO REPRODUCE
1. Create a .xmi file with umbrello.
2. Save and close it.
3. Try to open it.

OBSERVED RESULT
a pop-up error window appears:

The file <name_of_file.xmi> doesn't exists.

and the following error message is displayed in the console :

umbrello: view is NULL
umbrello: "folder"  : umlPackage not set on object
umbrello: screen dpi: 96 file dpi: 0 scale: inf
umbrello: UMLDoc::openDocument: copy from  QUrl("file:///home/arckaren/Documents/L3_INFO/Semestre_6/Projet_Final/Blokus/blokus_UML.xmi")  to  QUrl("file:///tmp/umbrello.weClBn") .
umbrello: UMLDoc::openDocument: temporary file < "/tmp/umbrello.weClBn" > failed!
umbrello: view is NULL
umbrello: "folder"  : umlPackage not set on object
umbrello: view is NULL
umbrello: screen dpi: 96 file dpi: 96 scale: 1
umbrello: folder= "Logical View"  / type= "Class"  / name= "Diagramme de classes"
umbrello: "Diagramme de classes"  to folder  UMLFolder: localName="Vue logique", folderFile="", diagrams=0  ( "Logical View" )
umbrello: id= "uD2z1KIZH0zrY"
umbrello: setZoom 100
umbrello: could not find  "Diagramme de classes"  in  UMLListViewItem: "Vue logique", type="lvt_Logical_View", id="Logical_View", children=1
umbrello: Changed view to UMLScene: "Diagramme de classes" / type="Class" / id="uD2z1KIZH0zrY" / isOpen=true
umbrello: setZoom 100


EXPECTED RESULT

The .xmi file is opened.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION