I have that system in an Imac
1Password Version: Not ProvidedExtension Version: Not ProvidedOS Version: Not ProvidedSync Type: Not Provided
As a security focused company we'd always recommend running the latest versions of all of your software, but especially your operating system, web browser(s), and 1Password. If you have a 1Password membership it may be possible to use 1Password v6 on Yosemite however even if this does work currently there is no guarantee that it would work at any point in the future. We're not financial advisors, and I know these devices are expensive, but if the device is old enough that it will no longer run the latest operating system it may be time to start planning for a newer model.
I'm sorry I don't have a more encouraging answer to share in this case.
Thank you Ben for your kind response. It is my main desktop a large I Mac with the latest OS version for that model. I was switching password managers to yours but in any case how i can get that version v6 for testing?
You're welcome. The legacy versions are available for download from the bottom of our downloads page: