Hello and welcome, when creating a new post, please use tags and the Q&A system. See Read Before Posting. I tried your code in a R20 script and it seems to work perfectly fine: rd = doc.GetActiveRenderData() if rd is None: return fromSlice = rd[c4d.RDATA_FRAMEFROM] toSlice = rd[c4d.RDATA_FRAMETO] fps = doc.GetFps() print(fromSlice.GetFrame(fps)) print(toSlice.GetFrame(fps) What exactly is not working for you? In what context do you execute your code? best wishes, Sebastian