Thunderbird calendar: CalDav fails after moving portable apps

Hi there,

just played around with ThunderbirdPortable's calendar (lightning). The calendar itself is working fine. Even if I move the PortableApps folder to another path Thunderbird and its calendar works nicely - as long as I use only local calendars.
This is not the case for caldav-based calendars. If I move portable apps I neither can access the caldav calendar nor can I create a new calendar. The entire calendar management got stuck.

How to reproduce
1. Install a fresh PortableApps, open it
2. Select and install ThunderbirdPortable from the directory
3. Start Thunderbird, ignore the email setup and close it again
4. Exit PortableApps
5. Move the PortableApps folder to another location
6. Start Thunderbird, open calendar tab
7. Create new calendar (left pane - right-click into 'Home' calendar - select 'New Calendar ...' item)
8. Select 'On the Network' then press Next
9. Select CalDav
10. Insert valid caldav address into Location field then press Next

Expected
Dialog to insert login credentials

Observed
Error message
An error was encountered preparing the calendar located at https://xxxxxxxx for use. It will not be available.

Details
[Exception... "Component returned failure code: 0x80570015 (NS_ERROR_XPC_CI_RETURNED_FAILURE) [nsIJSCID.createInstance]" nsresult: "0x80570015 (NS_ERROR_XPC_CI_RETURNED_FAILURE)" location: "JS frame :: jar:file:///D:/tmp/PortableAppsTest/PortableApps/ThunderbirdPortable/Data/profile/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D.xpi!/components/calItemModule.js -> resource://calendar/calendar-js/calCalendarManager.js :: createCalendar :: line 445" data: no]

Remark
iCalendar (ICS) is working fine

Hope somebody can fix it.

Best regards,
DomKla