Adding to what Mika suggested,   You can also check for any additional updates from with Acrobat and install them if there is one.     ... View more

>>>Can we keep an older version of InDesign etc. for opening those files? If yes, which is the latest version, which supports PostScript-Fonts?   Be sure to turn of the Creative Cloud app preference to revmove old versions. While you can usually install one version back, who wants the headache?   ... View more

Hi.  "Existing Type1 fonts will appear as “Missing fonts” in the document." "Many fonts published by Adobe Type in the past (such as Adobe Originals) are available from the Adobe Fonts service for free with your Creative Cloud subscription."   So, as I understand: you will be able to open .ai files that contain Postscript files but you will get a “Missing fonts” message, however, you can replace it. Some Postscript fonts could be available on Adobe Fonts and you can use the "auto-install" Illustrator function.   ... View more

This is the wrong place to ask for accurate info, experts on those products do not visit this forum. And type 1 fonts have no connection to PostScript today. Ask in each product forum, please - there may be a different answer.    Photoshop has already stopped type 1 support, you can test this yourself. Type 1 Font Support End of Life with Photoshop 23.0 Release (adobe.com) ... View more