First question to ask: what dchanged on your machine a few days ago? Updated software? A new bit of software? Different hardware? Considering how skittish AE CC 2014 can be on Yosemite Macs, it could be anything... even the seemingly-unconnected things.
Thanks for that. I actually tried to work that out, trying to think about what could have I changed, or done differently, or if I added any software but there hasn't been anything. I have been working several days without doing anything else. And what has been worrying is that it started being a very slight problem and it has been growing. I'm currently working around it not opening Premiere Pro and AE at once but one or the other and this way seems fine but of course far from ideal...
Does this happen with all projects, or just this one? If just this one, then what did you add to the project at the beginning of this problem?
I tried with other similar projects that didn't give me any problems in the past but again the same thing,
Ok I think I found a possible problem. One thing that we have changed in all these projects is a new design into the animations that has loads of files referencing directly from AI files. Could this be the problem?
I have done a test opening a new project importing some footage creating some DLs and adding several animations, without using any of the common elements that I have in my other projects and the problem is gone so I guess I have narrowed the likely culprits to a big group of assets, most of which are elements from AI files.
I found the problem. Nothing to do with AI files but with sheer amount of linked compositions, the moment I reach about 30 or so it begins slowing down.
Solution, keep the linked compositions in different AE projects. Works again like magic. Thanks for the help in any case!