I get an error around that same frame complaining it could not read a certain input AVI - but I can manually move the time cursor to that frame just fine, and the AVI is fine, too.
Actually I wouldn't be too certain of this. The error message pretty clearly seems to indicate that at that point no valid data exists. You may just not see any of this in the timeline, since - tata - AE does not preview fields. I think that's exactly what's happening. When rendering the second field, AE sends a request into nowhere and goes *poof*. Try rendering with all interlaced stuff turned off and it will render perfect. I'm 99% sure of that. To "fix" the problem, simply double the field at that position by putting a still image oif the first field in place, cutting away the offending 1 frame from the video.
first of all thanks very much for taking interest in my problem!
The composition as well as all the footage is non-interlaced, so not sure your suggestion applies. Also, the hang occurs on different frames each time, but very close to each other (I use the Render frame counter to tell where it hangs). In the meantime, I had AE write a Log file, tested the 'secret' preference options, tried to render shorter segements of the composition - all futile.
What I found out is that it is indeed caused by one specific video clip used in the composition. If I hide that, it renders fine. That clip is an AVI encoded using the (free, lossless) Huffyuv codec which, granted, is not supported and I am using it at my own risk but I never had any problems with it before, inlcuding older AE versions. I have converted that clip to another free, lossless codec (Lagarith) and now the composition is rendering.
It took me about five hours to find this out. I still have no good explanation, and I am certainly not impressed by AE's error recovery/reporting. :\
Yeah, such issues can annoy the hell out of one. HuffYUV hasn't been updated in eons, so you may experience a memory leak in the CoDec itself. I even de-listed it from my plug-in guide since it would be fatal to recommend it to people. Anyway, the reason it only exposes these problems now is probably due to newer versions of AE having this thing called MediaCore which tries to handle certain media formats, bypassing OS limitations and bugs such as incorrect Gamma. In older versions AE simply used Windows Media Components for this, regardless of CoDec. These may have responded more gracefully or even had specific pre-cautions for such scenarios. So basically, something that was meant to be good, worked against you this time. Well, but now that you know, you should be able to avoid such problems in the future. Glad you found out and reported back. Thanks for sharing the info.