We've encountered the following issues

When you ask a question you need to provide some basic information

-Forum quick start https://forums.adobe.com/docs/DOC-5601

Mac or Windows, and EXACTLY which version of the operating system?

Recent Mac AND Windows operating systems have been known to cause "odd" problems

Are you using a computer Administrator account with full read/write permission?

Exactly which version of the program do you have that is causing problems, and what error message do you see?

If new Mac and old program (CS6 and earlier) read below

CS6 and earlier programs have not been tested and will not be updated for Mac El Capitan or later operating systems

-which means that you try to use CS6 and earlier at YOUR risk of having problems due to Apple updates

-Apple did not maintain backward compatibility with old programs in El Capitan or Sierra

--Adobe has a workaround to Apple's problem of not maintaining backward compatibility

--READ HERE https://forums.adobe.com/thread/2301916 for an Adobe solution to installing old programs, including a link to installing the old Java runtime that is required

--Also read for more information https://forums.adobe.com/thread/2458382