I just upgraded from KMM 4.8 on Mint 18.2 KDE to KMM 5.0.1-2 on kubuntu 18.04. When I go to my bank and download transactions as .ofx file, I get a browser popup offering to open file with KMM (which is already running). If I accept the browser option KMM picks the correct account <ok>, then analyzes txns as duplicate, new, etc. When I click <ok> KMM crashes without importing any transactions. If I download the .ofx file, then chose "File->Import-> <dl.ofx>" from within KMM, it works fine. KMM is not logging into the bank. I do that on my own outside of KMM. I poked around for an error log but did not find anything.
*** This bug has been marked as a duplicate of bug 396831 ***