The CUDA message has nothing to do with not being able to save a project. Ignore that message for now.
We need to know a lot more if we're going to help you. Please provide answers to the questions listed here: "FAQ: What information should I provide when asking a question on this forum?"
Here are answers to the questions to the best of my ability.
Mac OS X 10.7.5
Warning : adobe could not create the file '/rainbow.logo.aep.'
I just been trying to set up my project and it will not let me save or save as. First I started on a project and tried to save it but it wouldn't work. I closed out and started over. I tried to save the project without adding any content but this message just keeps coming up.
I have created other projects in After Effects and have never had this problem.
Processor 2.4 ghz inetl core i7
8 gb 1067 mhz ddr3
Graphics AMD Radeon HD 6770M 1024 MB
I don't have an external driver (although I should!)
I installed CUDA 5.5.2 tonight and then I restarted my computer.
I have quicktime Version 10.1 (501.29)
I have the creative cloud and have installed indesign cc, premier pro cc, photoshop cc, and several other cc products. I tried to install Illustrator cc yesterday but it wouldn't let me and I didn't have time to trouble shoot that.
Let me know what other information is required.
You cannot save files on the root of your volume. You need to put it inside a folder. Also your file naming notation with all those extra points is just odd and will throw off your operationg system. Use underscores or just leave spaces.
Well I feel stupid- I am not sure how I missed that part- old age I guess. Just saved it to my project file- no problem. Thanks for your help.
btw I had simply named it Rainbow Logo- AE added all that other stuff- Not only would it throw off the operating system- it would throw me off- I would never remember what I had named it!