Yes.  2019.3 updated the database with new tables and fields and it updated the Connection Manager since the 2019.0 version.  When that happens, the older versions cannot open the data file.  You should have seen the warning when you opened the file on your system before the upgrade happened.

Technically your description

Nancy Fischer said:

They are both 2019 Pro

is contrary to what you have already said.  You are on the Accountant's Edition fully upgraded to 2019.3 and your client is on Pro using 2019.0.  The data file is at the Pro level because that is what your client can use.  Your AE version is all levels but not all releases.  You can only share files with a client on 2019.3 currently.

You didn't give us all the information about past file sharing, but you mention years and the client is using the current release starting version.  There must have been some issues in the past with updates and if not that means you never updated from the original.  So why did you update your version this year?

In the past I was able to restore different versions of the same year on his computer with no issues.   As the sage rep said I should be able to open 2019.3 on the computer with 2019.0 as she said as long as they are both using 2019 it should work. Perhaps we have just dodged bullets in the past that the different versions were only payroll tables related so never had a problem.  I don't recall seeing a warning when I upgraded to 2019.3.    I don't know if I can download the 2019.3 update to his computer from the sage website since it won't do it automatically as it says it's not eligible for updates but it won't hurt to try.   We need to resolve it as he needs access to his data.

Hello Nancy Fischer, 

Thanks for your post! Just want to clarify that the latest version available as of July 1st of Sage 50 CA is 2019.3. You'll want to install the update onto any machine running 2019 to bring it up to the newest version. The update can be downloaded for free here on KB 94858. 

Note that we provide updates for the latest version of the software plus 1 year back. Users don't need to have an active service plan in order to receive them.

If the latest update is not installed (when opening an upgraded file onto a machine running old software*), you're likely to encounter the Error: "Cannot open company file. A required data file is missing" when opening a data file or restoring from backup. See KB 12444 for more details, the above information would be mentioned in the section under causes.

Hope this helps!
Erzsi

Hi Erzsi

I didn't realise Sage changed the policy back to allow updates without subscriptions or I would have suggested Nancy just install from the file already on her computer.

Thanks for letting us know.

Hi Nancy,

You can get all downloaded update files from this location on your computer as well.

C:\Users\Public\Documents\Sage Software\Simply Accounting\Download

I guess you hit the few versions that don't change database formats.  I believe the update from 2019.0 to 2019.1 allowed 2019.0 to open a 2019.1 file (with warning).  However, I would think that rep was confused about the situation upgrading past 2019.2 (which changed the database and Connection Manager).

Hi Richard S. Ridings, if Nancy Fischer's client was on version 2018, then the 2019.3 update wouldn't help them as they would need to have purchased / have access to the 2019 version activation. We provide the updates but they can only be installed and applied to the latest version if you're on an active subscription or purchased the most recent license at retail.

We're launching the 2020 version soon, only those with active subscriptions will be entitled to new serial numbers and activation codes for it. Updates for it thereafter can be installed for free as long as they have full access to the base 2020.0 version.

Hope this helps clarify :).

Thanks Erzsi.  That is what I've been doing the last several years.  When 2020 comes out and I upgrade to that, I still keep my 2019 for that one client going until he can purchase the 2020 off the shelf then I move him to that version.   I assume that because he does not have a subscription that the updates are not automatic but I am allowed to download and install the 2019.3 manually.  Will try that when I am at his office later.  Will report back if all is ok.

Yes it does, thanks.

success!  Although after installing the update it took 3 restores to get the file open as the first 2 times after I did the restore for some reason the .sai files were missing.  But all good again.

Glad you got it worked out.