What is the consequence of keeping old versions of Adobe applications?

What could be the reason why you would need a previous version? 

By @Randi31153221ofz3

Some reasons which spring to my mind:

1. Plugin compatibility - sometimes older plugins are not compatible with newer versions
2. Maintain access to "legacy" (which Adobe calls them) tools and features in older versions which have been deprecated (removed) in new versions.
   Adobe may deprecate features because the legacy code which powers the old features means updating is no longer feasible. Could be too time consuming or a security issue or the people with the old coding skills have moved on to new technology. Or there is simply a better (according to Adobe) way to do something with a new feature.
3. You're collaborating with people who have older versions and don't have the new features or tools.
   Note: It's of course still possible to collaborate if you have a newer version than others but collaborating in older workflows may still be a reason to keep an older version on hand.
4. You simply prefer working with an older version. For example, perhaps you've got a decades old workflow - which is no longer applicable in new versions - that you don't feel the need to change.

If none of those apply to you then feel free to delete the older versions.

I always keep old versions of Adobe software installed. 

It depends upon the specific software, but sometimes features that were used in old projects are removed, and you might not be able to open old projects.

The only downside is that if you are short on disk space, it may be problematic.  However, if you are that short on disk space, performance would soon become an issue.

Hello,

Thanks for writing in. Adobe always advises to use the latest version to make use of the latest features available in compatibility with the latest OS updates.

However, this is everyone's personal choice. Some users keep older versions of the apps as they are more habitual of using them.

There is no direct loss of keeping the older versions other than occupying space on your computer if you are using the latest versions.

Having said that, every application operates differently.

but what is the consequence of uninstalling the previous versions? Will I not be able to for example open an InDesign document made and saved in a previous version? 

What could be the reason why you would need a previous version? 

I looks to me like they just take up a lot of space ....

By @Randi31153221ofz3

It would be more appropriate to be answered by the product expert. Let us know if you have query for any spcific product. We'll direct you there. 🙂 

Regards,

Shivangi

old versions generally can be opened with with newer versions.  ie, if you see no problems after a few months of using, uninstall your older version(s)