After upgrading I have lost two months data. no entry or accounts during that time. (Q Mac)

I'm sorry, but your post doesn't provide enough data to zero in on the source of the problem.

First, what "forceful upgrade" are you referring to? Quicken or macOS? Quicken never forces anyone to upgrade; it only display a box that a new version is available, but you can always dismiss it and continue using your current version. (Likewise, macOS updates can always be skipped.) Just something to know for the future…

Now, to your specific issue: you're saying you lost two month of data. This is data which was in your Quicken, which then disappeared after your upgrade? I have not heard any instances where Quicken lost months of a users' data, so I think one of two things are in play here:

(1) Are you certain you have no date filters in the register(s) or report(s) you're looking at, and that your register is sorted in date order? Try this:

• click on All Transactions in the left sidebar
• Make sure the filters show "All Dates", "All Accounts" and "Any Status"
• Click once to twice on the Date heading so that the register is displayed in date order

Do you now see any of the transactions you previously entered from the past two months?

If not, you may need to look at...

(2) Do you have the most current version of Quicken open? Quicken keeps track of the last opened data file, but it's possible for this to become out-of-sync. So you may want to look in the folder where your data file is saved to make sure there isn't another version of your data file which has the more recent transactions.

What version did you upgrade from? I was assuming you were using a relatively recent version and had just upgraded to version 6.3.  Were you instead upgrading from the old Quicken 2007? (If so, it seems likely you imported an older Quicken 2007 data file than your most recent one; if you can locate the newer file, you will be able to import it and carry on from there.)