File & Image Upload not working on server

I’m installing Sitecake on a site, but if I try to upload a file/image, it fails, and gives an error of “An error has occured during the file upload process. Internal Server Error”
Chrome console is showing this:

POST [website]/sitecake/2.2.10/server/admin.php?service=upload&action=upload 500 (Internal Server Error) com_sitecake_contentmanager_client_upload_UploadManagerImpl$uploadNextFile__Lcom_sitecake_contentmanager_client_upload_UploadManagerImpl_2V @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:29668
com_sitecake_contentmanager_client_upload_UploadManagerImpl_$uploadNextBatch__Lcom_sitecake_contentmanager_client_upload_UploadManagerImpl_2V @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:29640
com_sitecake_contentmanager_client_upload_UploadManagerImpl_$upload__Lcom_sitecake_contentmanager_client_upload_UploadManagerImpl_2Lcom_sitecake_contentmanager_client_upload_UploadBatch_2V @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:29613
com_sitecake_contentmanager_client_item_fileuploader_FileUploaderItem_$enterUploadingPhase__Lcom_sitecake_contentmanager_client_item_fileuploader_FileUploaderItem_2V @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:19049
com_sitecake_contentmanager_client_item_fileuploader_FileUploaderItem$1_execute__V @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:19255
com_google_gwt_core_client_impl_SchedulerImpl_runScheduledTasks__Lcom_google_gwt_core_client_JsArray_2Lcom_google_gwt_core_client_JsArray_2Lcom_google_gwt_core_client_JsArray_2 @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:2759
com_google_gwt_core_client_impl_SchedulerImpl_$flushPostEventPumpCommands__Lcom_google_gwt_core_client_impl_SchedulerImpl_2V @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:2681
com_google_gwt_core_client_impl_SchedulerImpl$Flusher_execute__Z @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:2811
com_google_gwt_core_client_impl_SchedulerImpl_execute__Lcom_google_gwt_core_client_Scheduler$RepeatingCommand_2Z @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:2713
com_google_gwt_core_client_impl_Impl_entry0__Ljava_lang_Object_2Ljava_lang_Object_2Ljava_lang_Object_2Ljava_lang_Object_2 @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:2614
(anonymous function) @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:2599
(anonymous function) @ 05E9B37ED204710E41551EC5ED01F0CE.cache.html:2777

Image cropping works, which means that Sitecake can successfully create new files, but upload fails.
I’m running this with the example Portfolio Template and Sitecake 2.2.10
It works perfectly on my computer’s localhost.

Any help would be lovely.

Solution found!
I downgraded from PHP v5.5.17 to PHP v5.4.34, since this page said that Sitecake “requires PHP 5.4+”, and file upload works now!

Any thoughts on when the app will be compatible with 5.5+? Seeing that 5.4 is END OF LIFE it would be good to be current. Also with 5.6+ out seems lazy not to have an app that works on the current platform. Not everyone will have the ability to downgrade.

Latest release of sitecake that should be out tomorrow is tested with PHP 5.6