Important: Be sure to install the recent updates for After Effects CS5 and Adobe Media Encoder. These updates fix many bugs.
See the After Effects 10.0.2 release notes for other known issues.
See this Technical Support document for more information and solutions.
Workaround: Relink footage after opening.
When Memory and Multiprocessing is enabled for "Render Multiple Frames Simultaneously," frames cached by foreground processes can be purged when you initiate a second RAM preview. (54071 and 53844)
When you render to the MPEG4 output module, avoid enabling the "Short Header" parameter under "Format Options," if possible. Enabling this option can cause various problems with the rendered media file. (54118)
Some composition sizes can result in improperly constrained output media sizes. This issue occurs when you use the MPEG-2 output module with certain non-default combinations of the "Profile" and "Level" parameters under Format Options (54115).
AVI files rendered with the "None" codec from compositions that don't match the target output file's dimensions can be restricted to a square pixel aspect ratio. (2563466)
The Turbulent Noise effect can crash After Effects when rendering to the FLV output module with a low value in the "Undershoot" parameter (54113).
Live Photoshop 3D models do not redraw when modifying camera properties if motion blur is enabled; workaround is to purge the image cache (54123).
If you minimize After Effects while Live Photoshop 3D is engaging the ray traced renderer, it doesn't come back to the foreground until rendering is complete. A workaround is to engage Caps Lock to disable rendering (2579653).
The "MediaCoreQTCodecRulesCS5.xml" file isn't loaded when opening pre-CS5 projects that have the "Match Legacy After Effects QuickTime Gamma Adjustments" checkbox enabled. (The MediaCoreQTCodecRulesCS5.xml file governs color handling behaviors in some QuickTime codecs.) This issue can cause incorrect handling of gamma or color values in QuickTime source files (2572685).