I have been using roto brush on a few projects lately but have come up against an issue I just can't fix. I have gone through my sequence and roto brushed out all the areas I needed to. I was doing this frame by frame as there are some tricky areas. If I then render, it doesnt seem to render out the whole sequence, it does a bit and then goes frame by frame, ie I lose all the preceeding green indicator. The main problem is that is hangs on a frame 60 of my sequance. I have looked and there is nothing unusual there. In rendering mode, I have on occassion been able to move past this by rendering frame by frame (ie command+right arrow) althought it takes forever. However, I cannot render the whole sequence with issue mentioned about. Now when I try and 'Freeze', then I get to frame 60 and then I get the magic beachball and AE freezes so I have to force quit. Any help would be greatly appreciated as I have a dealine looming. Thanks
Your screenshot doesn't tell us much. The mask might not preview when freezing Rotobrush. There could be other problems. Please embed your screenshots using the toolbar. The Drag and Drop here... space is buggy and a pain for us to look at.
AE locking up could be a combination of a bunch of factors. It all depends on how complex your rotobrush is. Many times I'll throw a bunch of color correction on the layer I'm going to roto to clean up the edges, then pre-compose the shot and run Rotobrush on the Pre-comp. When you're done you can either remove the effects, or better yet if the shot is complex, Pre-compose the Rotobrush layer moving all attributes, then render and replace using the Composition menu and a lossless with alpha preset.
Transcode your stock footage into a different file format would suggest ProRes 444 on a Mac, use all the same frame rates and pixel resolutions in Media Encoder as the original file.
Once that has rendered out replace the footage with the new file you just encoded and continue your project Roto brushing.
I suggest this because I think you may have a frame that contains an error that AE is failing to debayer properly. If the transcode fails at the Media encoder stage then you will have to get a fresh copy of the .mov file as the working copy you have in your project is corrupted.