SUMMARY When opening mails containing a calendar invite (multipart/alternative with parts text/plain, text/html, and text/calendar), kmail nicely formats them, with buttons for invitation response actions. However, it takes a long time for these messages to be rendered, i.e., the time between opening them and seeing anything but white is long (23 seconds on a very fast laptop), which makes the feature inconvenient. STEPS TO REPRODUCE 1. Open calendar invite mail OBSERVED RESULT See blank space for a long time EXPECTED RESULT See rendered invite almost immediately SOFTWARE/OS VERSIONS KDE Plasma Version: 5.96.0 KDE Frameworks Version: 5.96.0 Qt Version: 5.15.5 ADDITIONAL INFORMATION In my logs, I see the following right after opening the calendar invite mail. I assume that this activity is related to the fact that a list of nearby events are shown at the bottom of the invite mail. I assume that something going wrong here is what causes the large delay. akonadiserver[1617]: org.kde.pim.akonadiserver.search: Executing search "kmail2-3636980645-SearchSession" akonadiserver[1617]: org.kde.pim.akonadiserver.search: Search "kmail2-3636980645-SearchSession" done (without remote search) akonadiserver[1617]: org.kde.pim.akonadiserver: ItemRetrievalJob for request 511 finished akonadiserver[1617]: org.kde.pim.akonadiserver: ItemRetrievalJob for request 512 finished kmail[2754]: parse error from icalcomponent_new_from_string. string= "" kmail[2754]: org.kde.pim.calendar_serializer: Failed to parse incidence! Item id = 323784 Storage collection id 209 parentCollectionId = -4134 kmail[2754]: org.kde.pim.calendar_serializer: "" kmail[2754]: org.kde.pim.akonadicore: Unable to deserialize payload part: "RFC822" in item 323784 collection -4134 kmail[2754]: org.kde.pim.akonadicore: payload data was: "" [LAST 5 LINES REPEATED 9 TIMES FOR DIFFERENT ‘items’ AND TWO DIFFERENT ‘collections’] akonadiserver[1617]: org.kde.pim.akonadiserver: ItemRetrievalJob for request 515 finished akonadiserver[1617]: org.kde.pim.akonadiserver: ItemRetrievalJob for request 514 finished kmail[2754]: org.kde.pim.akonadicalendar: Discarding event with invalid DTSTART. identifier= "bcf67360-f30a-47c5-b40c-7ea81db35e6a_KABC_Birthday" ; summary= "Verjaardag van <a contact>" kmail[2754]: org.kde.pim.akonadicalendar: Discarding event with invalid DTSTART. identifier= "15f9ece3-7d43-4705-b29d-7ae65ce45c60_KABC_Birthday" ; summary= "Verjaardag van <another contact>" kmail[2754]: kf.calendarcore: hierarchy loop between "5a0b7b9c-81ad-456f-bfdc-6b8c285c356e" and "9884a435-85fd-435d-b300-367cfb2968bb" [LAST LINE REPEATED 10 TIMES FOR DIFFERENT PAIRS OF UUIDS] kmail[2754]: org.kde.pim.akonadicalendar: Unable to fetch incidences: "Invalid item or payload: 308122" [LAST LINE REPEATED 236 TIMES FOR DIFFERENT ‘items’] kmail[2754]: org.kde.pim.text_calendar: Unable to fetch incidences: "Invalid item or payload: 313658" kmail[2754]: kf.xmlgui: Index 86 is not within range (0 - 20 )