I don't know if this helps, but on the console I have this error:
=================
Error: nextOcc is null
Source File: resource://calendar/modules/calUtils.jsm -> file:///C:/Program%20Files/_Portable2/ThunderbirdPortable<email address hidden>/js/soapin.js
Line: 393
====================
I found "nextOcc" variable on function "makeDismissSnoozeState(aItem, e)" line 470
It seams it is linked with this problem.
I don't know if this helps, but on the console I have this error: //calendar/ modules/ calUtils. jsm -> file:// /C:/Program% 20Files/ _Portable2/ ThunderbirdPort able<email address hidden> /js/soapin. js ======= ======
=================
Error: nextOcc is null
Source File: resource:
Line: 393
=======
I found "nextOcc" variable on function "makeDismissSno ozeState( aItem, e)" line 470
It seams it is linked with this problem.