Looking at my journal, it seems there are a lot of the following as well. Can anyone offer any assistance?
May 10 22:16:06 localhost plasmashell[2530]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 59191, resource id: 111149084, major code: 142 (Unknown), minor code: 3
May 10 22:16:07 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 59345, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:16:07 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 59377, resource id: 130023574, major code: 142 (Unknown), minor code: 3
May 10 22:16:48 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 62681, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:16:48 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 62751, resource id: 138414480, major code: 142 (Unknown), minor code: 3
May 10 22:17:16 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 64695, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:17:16 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 64742, resource id: 130023574, major code: 142 (Unknown), minor code: 3
May 10 22:18:24 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 3881, resource id: 111149057, major code: 142 (Unknown), minor code: 3
May 10 22:18:25 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 4040, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:18:58 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 6926, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:18:58 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 6948, resource id: 138414480, major code: 142 (Unknown), minor code: 3
May 10 22:18:58 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 7061, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:18:58 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 7275, resource id: 130023574, major code: 142 (Unknown), minor code: 3
May 10 22:19:05 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 1468, resource id: 27449249, major code: 3 (GetWindowAttributes), minor code
May 10 22:19:05 localhost kwin_x11[2523]: QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1469, resource id: 27449249, major code: 14 (GetGeometry), minor code: 0
May 10 22:19:05 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 1472, resource id: 27449249, major code: 3 (GetWindowAttributes), minor code
May 10 22:19:42 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 10494, resource id: 111149057, major code: 142 (Unknown), minor code: 3
May 10 22:19:53 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 11516, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:19:53 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 11565, resource id: 138414480, major code: 142 (Unknown), minor code: 3
May 10 22:19:53 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 11642, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:22:19 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 45306, resource id: 111149091, major code: 15 (QueryTree), minor code: 0
May 10 22:22:24 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 21346, resource id: 130023574, major code: 142 (Unknown), minor code: 3
May 10 22:22:24 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 21495, resource id: 138414480, major code: 142 (Unknown), minor code: 3
May 10 22:22:33 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 22393, resource id: 138412068, major code: 142 (Unknown), minor code: 3
May 10 22:22:44 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 54637, resource id: 138414480, major code: 15 (QueryTree), minor code: 0
May 10 22:22:49 localhost plasmashell[2530]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 23441, resource id: 138414480, major code: 142 (Unknown), minor code: 3
May 10 22:22:51 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 58547, resource id: 138418987, major code: 15 (QueryTree), minor code: 0
May 10 22:23:11 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 3286, resource id: 138412068, major code: 15 (QueryTree), minor code: 0
May 10 22:34:56 localhost plasmashell[2530]: QXcbConnection: XCB error: 2 (BadValue), sequence: 65358, resource id: 111149057, major code: 142 (Unknown), minor code: 3
May 10 22:35:19 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 38521, resource id: 119537680, major code: 15 (QueryTree), minor code: 0
May 10 22:35:19 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 38761, resource id: 121634820, major code: 18 (ChangeProperty), minor code:
May 10 22:35:21 localhost kwin_x11[2523]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 39477, resource id: 111149057, major code: 15 (QueryTree), minor code: 0
May 10 22:35:27 localhost plasmashell[2530]: QXcbConnection: XCB error: 3 (BadWindow), sequence: 1754, resource id: 119537680, major code: 142 (Unknown), minor code: 3