Hi, I'm Robert and I'll be helping you with your financial software question.
copy the data file to another folder and give it a new name
highlight this new file and hit command I to see the properties
make sure that it is not set to read only or hidden or system
then try to double click on it and see if it will open
If the problem is not with the data file
see if you can open the quicken program from the application folder
if you can not do that.
drag it to the trash can
reboot the computer
install it again
If you purchased from Intuit directly you can download again for 3 years.
go to https://quicken.intuit.com/commerce/account/secure/login.jsp?pagecontext=download
sign in with the email address and password XXXXX you used when you purchased it
click on downloads and unlocks
That should give you a list of any intuit product that you purchased online within the last 3 years with a download button. Click the download button next to the product that you want and then select RUN.