thank you so much for the reply.
I have FCP HD.
I will try the log and transfer this evening. Thank you for the advice.
btw. I tried to convert ACI on a different mac with Streamclip and used the FCP (without “HD”) and it worked! No red bar! So it definitely is because of the FCP HD version.
I hope log and transfer will work for me. It can’t be that I cannot edit/convert any h.264.
could it also be a problem of memory? (have 2 GB memory and the ACI data clips are about 300MB each. but it should not be a problem… FCP would rather shut down than merely showing the red bar)