same problem here
when i try to export rendered shapes i always get:
"failed to render: no valid frames in clip" and the progress bar contantly flashes from 0 to 100% and then the error
"failed to save image: colourspace parameters not found" appears..
however.. when i choose a clip in the "clip to show in main window" drop down menu that is not my input video (so that its not displayed) it exports correctly without errors.. at least in image sequence mode..
i'm on a mac and the input footage was a 1920x1080@25p apple pro res 4:2:2 file (originally recorded on xdcam hd) that i converted to photo jpeg because mocha didn't like the pro res one.