Had some problems trying to export an AEC file from C4D R15 this morning and wanted to share a workaround a coworker let me know about. When using the physical renderer I was unable to export an AEC file. My computer, a windows PC, would hang up and require a force quit.
By changing the renderer back to standard, I was able to export the AEC file as usual. I still rendered my scene with the physical renderer, but then switched back to the standard renderer just to export my AEC.
Pretty silly.