I have just purchased qcad-2.2.2.0-1 (linux) and it crashes as soon as I try to open / save a file.
the following is written to the console before the crash:
QFileSystemWatcher: failed to add paths: /
QObject::connect: Cannot queue arguments of type 'QTextCursor'
(Make sure 'QTextCursor' is registered using qRegisterMetaType().)
Everything else works fine (I can open files from the command line and save then by clicking the save icon).
I have also tried to delete the QCAD.ini as suggested in other posts, but that did not help....
Jerome
