have Adobe just placed a time limit on their software??
As far as I understand not directly.
If an installation runs on the corresponding old OS it should run fine but in your case something seems to have been messed up.
If you have a legitimate license for up to Photoshop CS2 you should be eligible to download, install and register Photoshop CS2 for free.
Please read this
Many thanks for your help. I do have a legitimate CS license so I shall follow the instructions in the link.
And check out the "What’s New" section in the Help, Smart Objects were introduced with CS2, though not Smart Filters yet …