Hello, I also experienced failure of KMyMoney after recent updates with same messages. In my case I am using Mate, the full output from terminal is:
WebConnect: Try to connect to WebConnect server
WebConnect: Connect to server failed
WebConnect: Running in server mode
System icon theme as reported by QT: "menta"
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
QPainter::begin: Paint device returned engine == 0, type: 2
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kbanking.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kcm_icalendarexporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/gncimporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/konlinetasks_sepa.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/qifexporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/budgetview.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/icalendarexporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/reportsview.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/reconciliationreport.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/csvimporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/onlinejoboutboxview.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kcm_reportsview.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/forecastview.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/csvexporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/sqlstorage.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kcm_csvimporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kcm_qif.so" Validity false
Located plugin "/usr/lib64/qt5/plugins/kmymoney/ofximporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/qifimporter.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kcm_forecastview.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/checkprinting.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kcm_xmlstorage.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/xmlstorage.so" Validity true
Located plugin "/usr/lib64/qt5/plugins/kmymoney/kcm_checkprinting.so" Validity true
Loading "/usr/lib64/qt5/plugins/kmymoney/budgetview.so"
Plugins: budgetview loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/checkprinting.so"
Plugins: checkprinting loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/csvexporter.so"
Plugins: csvexporter loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/csvimporter.so"
Plugins: csvimporter loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/forecastview.so"
Plugins: forecastview loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/gncimporter.so"
Plugins: gncimporter loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/icalendarexporter.so"
Plugins: icalendarexporter loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/kbanking.so"
"Plugins: kbanking loaded, build with (5.4.1stable-0/6.2.5.0stable), run with (5.4.1.0/6.2.5.0)"
3:2022/09/03 22-45-06:(null)(4081):banking_update.c: 610: No AqBanking config folder found at [/home/luca/.aqbanking/settings6/users] (-1)
3:2022/09/03 22-45-06:(null)(4081):banking_update.c: 610: No AqBanking config folder found at [/home/luca/.aqbanking/settings/users] (-1)
3:2022/09/03 22-45-06:(null)(4081):banking_update.c: 411: There is no old settings folder, need initial setup
7:2022-09-03 22:45:06:aqbanking started
Loading "/usr/lib64/qt5/plugins/kmymoney/ofximporter.so"
Plugins: ofximporter loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/onlinejoboutboxview.so"
Plugins: onlinejoboutboxview loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/qifexporter.so"
Plugins: qifexporter loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/qifimporter.so"
Plugins: qifimporter loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/reconciliationreport.so"
Plugins: reconciliation report loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/reportsview.so"
Plugins: reportsview loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/sqlstorage.so"
Plugins: sqlstorage loaded
Loading "/usr/lib64/qt5/plugins/kmymoney/xmlstorage.so"
Plugins: xmlstorage loaded
Segmentation fault (core dumped)