Some video codecs and file formats cause more problems than others. Tell us more about your project. What kind of footage? OS and AE version down to the last decimal point would also be helpful.
Thanks for the response, Rick. I'm on OSX 10.9.5 and AE CC 2014.1.1 Version 184.108.40.206.
I actually already deleted all of the footage out of the main comp and out of the two precomps I left in there. The footage I had in there before is Quicktime 1080 ProRes 4444 using RGB+A which I've used many times before without this issue. There are no audio files in there either.
I am doing some character animation and other stuff with Illustrator CS6 files and shape layers. There are some nulls and solids and quite a few expressions for the character rigs (IK, etc). Some 3D layers and cameras are involved. I'm using very few effects- mostly fills and tints and the Puppet Tool.
Anything else you need to know?
Hi Natevplas, this seems to be a massive issue at the moment. I have several colleagues working on AE CC 2014 and we all have the Locking Existing Frames issue!! It appears to have reared it's ugly head again as I'm sure it was cured several versions ago.the cure apparently seems to be turning off the audio, but I can't turn the audio in my project off for rendering as I need to see it working with the pictures....so a catch 22 situation!!!
Please, Please, Please Adobe sort this out as it is seriously hampering productivity!!
I look forward to a swift response.
I was struggling with this issue recently and (at least for me) the problem could be related to the sample rate/bit depth of the audio files being used. I noticed it occured when I added a couple of VO recordings to my comp so I made sure to convert the audio files to 24bit 48khz and reimported into the project. The problem went away but of course it may just be that deleting the files from the project and reimporting them fixed the issue and changing the bit/sample rate was a placebo!
Yes, it seems that the processing of the audio for the preview is what is causing the delay. Try muting the audio in the Preview panel, and I expect that you'll see this delay go away.
if i could have seen your face when you wrote that, were you blushing with embarrassment? don't work with audio. sheesh, that's useful. (anybody able to work without audio?) multi-processing for previews is basically non-functional here. preview with multi-processing just doesn't work, with 32 gigs of ram and a fast external drive, afx gives the locking frames message and then sits there. this is on light comps even with no audio. had to turn off multi-processing for previews to even work. i'd hope there was a more immediate fix you could come up with, even short term, than turning off the audio and waiting for the rewrite of the afx core code.