Mathcad Prime 3.0 compatibility - I cannot open old files now

[TS_7161516]

I've been using Mathcad Prime 3.0 for a few years now.  With annual subscriptions, I'd expect that updates would keep me current, but seeing that there's a version 11.0 now, looks like I was wrong.  

My IT department loaded 3.0 on my new laptop, which should have been the same as on my old desktop, but I cannot open the files created previously.  I get the message "This file is not compatible with your current version of Mathcad, because it is from a more recent version of Mathcad".  

Any ideas on why this is happening?  

What later versions of Prime would still be able to open these 3.0 files?

[Werner_E · Accepted solution]

Prime is not auto-updating.
You have to download the latest version yourself. let PTC create a new license file and then install it. Its up to you if you remove the old version or have them installed side by side.

No idea why you may not be able to open a Prime 3 file in Prime 3 as any version of Prime 3.0 (apart from different language settings there is only one version anyway - OK there also was a version 3.1) should be able to open your old Prime 3.0 files.

But once you open a 3.0 file with a newer version of Prime like Prime 11 and save it (!), the file will be in the new Prime format and no older version it will be able to open it. You would not be able to open it again in Prime 3. Prime is also not able to save a file using an older format so that older versions can read it like other software might be able to do - guess that's done that way on purpose by PTC.

On the other hand - if you never opened and saved the file in a newer version than Prime 3, you should still be able to open it in Prime 3. Exception is that the file somehow got corrupted which unfortunately according to postings here in the forum happens quite often. But then the error message would be differently, telling you that the file is not a valid Prime file.

I am surprised that your IT department was able to load P3 on your laptop because as far as I am aware Prime is only available via subscription which means you have to pay year for year for the software and versions below Prime 7 are not supported anymore by PTC and no licenses will be created for it because of licensing issues (the older versions contain an old version of Mathworks muPad for symbolic calculations).

Any later vere