If I go to http://www.inf-it.com/caldavzap/‎ then Firefox crashes after a few seconds. I can reproduce the problem using my own copy of caldavzap.

The crash details are: AdapterDeviceID: 0x944a AdapterVendorID: 0x1002 Add-ons: https-everywhere%40eff.org:3.4.2,%7B972ce4c6-7e08-4474-a285-3208198ce6fd%7D:25.0,%7Bd10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d%7D:2.4,en-gb%40flyingtophat.co.uk:1.19.5,jid1-ZAdIEUB7XOzOJw%40jetpack:0.3.8,firefox%40ghostery.com:5.0.6 BuildID: 20131025151332 CrashTime: 1384467323 EMCheckCompatibility: true InstallTime: 1383213547 Notes: AdapterVendorID: 0x1002, AdapterDeviceID: 0x944aGL Layers! GL Context? GL Context+ GL Layers+ xpcom_runtime_abort(###!!! ABORT: Attempt to create unsupported SourceSurface fromnon-image surface.: file /builds/slave/rel-m-rel-osx64_bld-0000000000/build/gfx/thebes/gfxPlatform.cpp, line 732) ProductID: {ec8030f7-c20a-464f-9b0e-13a3a9e97384} ProductName: Firefox ReleaseChannel: release SecondsSinceLastCrash: 415 StartupTime: 1384467305 Theme: classic/1.0 Throttleable: 1 URL: http://www.inf-it.com/caldavzap/ Vendor: Mozilla Version: 25.0 Ce rapport contient également des informations techniques sur l'état de l'application lors du plantage. If started from a terminal I also have: Nov 14 23:16:25 iMac-de-Ludovic.local firefox[3175] <Error>: CGImageCreate: invalid image size: 0 x 0. ###!!! ABORT: Attempt to create unsupported SourceSurface fromnon-image surface.: file /builds/slave/rel-m-rel-osx64_bld-0000000000/build/gfx/thebes/gfxPlatform.cpp, line 732 ###!!! ABORT: Attempt to create unsupported SourceSurface fromnon-image surface.: file /builds/slave/rel-m-rel-osx64_bld-0000000000/build/gfx/thebes/gfxPlatform.cpp, line 732

I do not have the problem using the beta version 26.0b4. Maybe it is an already known and fixed bug.

Please load about:support and copy the information in the Graphics section here (using the version that crashes).

"graphics": { "numTotalWindows": 1, "numAcceleratedWindows": 1, "windowLayerManagerType": "OpenGL", "windowLayerManagerRemote": true, "adapterDescription": "", "adapterVendorID": "0x1002", "adapterDeviceID": "0x944a", "adapterRAM": "", "adapterDrivers": "", "driverVersion": "", "driverDate": "", "webglRenderer": "ATI Technologies Inc. -- ATI Radeon HD 4850 OpenGL Engine", "info": { "AzureCanvasBackend": "quartz", "AzureSkiaAccelerated": 0, "AzureFallbackCanvasBackend": "none", "AzureContentBackend": "quartz" } },

My crash report brings me to https://crash-stats.mozilla.com/report/index/5e1a7476-06cf-4c54-a22e-1b1ab2131114 My bug may be similar to https://bugzilla.mozilla.org/show_bug.cgi?id=844819

Given that this page uses SVG, the reading of bug 936087, then you saying it's fixed in 26 and bug 844819 is indeed fixed in 26, I'll call this a duplicate. Thanks for reporting, though, it's better finding a duplicate than ignoring an issue and never get it filed. :)