Please try following steps.
1) Open up Finder
2) From the menu bar, select Go > Go To Folder
3) Type in "~/Library" and select Go
4) Once in the Library folder, select Preferences
5) Right click on the Adobe folder and select Get Info
6) Click the lock on the bottom right corner to allow changes
7) Expand the Sharing & Permissions portion at the bottom
8) Change Priveleges for Staff and Everyone to Read & Write
Note: To assign the permission right click on adobe folder and click Get info.. A property window will open. Then click on lock symbol to enable editing. Then click + sign to add your username. Then change read only to read and write. Then click gear symbol at the bottom and click apply to enclosed items and click ok..
Thank you! I've tried this but still get the error. It's upon opening After Effects