Discovered and can be reproduced with DavDroid 0.8.0, which is the first version using REPORT.From https://issues.kolab.org/show_bug.cgi?id=3049:
On some calendar URLs```
If a VEVENT object has a full URI as its unique identifier, invalid CalDAV URLs for these objects are created and thus synchronization fails. For example, althoughevents from the PROPFIND succeedsf1calendar.com feed look like this:
"PROPFIND /calendars/greve@georggreve.net/c81425b202e6-3182008d3351-2712f63c/ HTTP/1.1" 207 1018 "-" "DAVdroid/0.8.0" SUMMARY:Australian Grand Prix
UID:http://2014.f1calendar.com#GP1_2014
a REPORT on the same URL then fails with 404In a multistatus request, iRony produces invalid URIs like this:
"REPORT <d:href>/calendars/greve@georggreve.net/c81425b202e6-3182008d3351-2712f63c/ HTTP/1.1" 404 739 "-" "DAVdroid/0.8.0"john.die%40mykolab.com/ff228802b9-53dabd4f3356-f270fcdd4/http://2014.f1calendar.com#GP1_2014.ics</d:href>
See https://github.com/bitfireAT/davdroid/issues/542 for more information.which is wrongly encoded and when a client wants to fetch such an event a "Object not found" exception is returned.
```
The original fixes are in rI4561e85 (then master, now 0.3) and rIe916334 (0.2), and should have been resolved as per version 0.2.9.
It cannot be reproduced on current master (0.4), but it seems to occur on 0.3.0 (caldav.kolabsys.com) but not on 0.3 (developer workstation).