Thanks for your message!
Here is the output of the console, combined with the error dialog that pops up:
Unfortunately I can not add the full image inline as the forum removes that...
I have added the JAVA_VM and JAVA_HOME var as debug output.
This error in starting ACC comes when using incompatible JDK. I remember that ATG 9.1 was supported with JDK 1.5 and support for Java 1.6 came later through a patch release (this was before Oracle acquisition). If you want to continue using JRE 1.6 then I think only possible way to do so is to use ATG9.4 or install the patch if you have it on your 9.1 setup.
On Mac, you can check the location /System/Library/Frameworks/JavaVM.framework/Versions and see if you have folder corresponding to Java versions 1.6, 1.5, etc. If 1.5 is there then you can make 1.5 as your current JDK by opening terminal, changing to /System/Library/Frameworks/JavaVM.framework/Versions and then executing:
sudo ln -fhsv 1.5 CurrentJDK
After this if you execute "java -version" in a new terminal then it should show you 1.5. You need not worry about making a lower JDK as your default as this process is completely reversible and you can change your default JDK later. Do make sure that your .bash_profile doesn't have any Java path entry pointing to another version than what you have set for your current JDK. Also ensure that you have created a dasEnv.sh at the path ATG9.1/home/locaolconfig/dasEnv.sh with following line in it:
Hope it helps.