How to delete "common data" on PS4?

[Kid Yeti]

Hi, I have seen this suggestion to delete "common data" as a solution to PS4 issues.  How is this done exactly?  I can't seem to find where I can delete it. I see it as an option to upload or download to/from storage, but to outright delete it.

Specifically, I am trying to fix a crash with error CE-34878-0 whenever I try to reload a certain saved game.  It has happened before but I downloaded a saved copy that I had uploaded a week before.  Now it's happened again and I assume something more fundamental is wrong.

Is this the result of a corrupted save?  Is that what CE-34878-0 means?

Also, a general question on "common data" - if it's not deleted will it ruin my other saved KSP games?  I seem to be able to load other saved games and start new ones.  Is deleting it a routine maintenance practice I just be doing often?  Is there downside to deleting it?

Running PS4 Enhanced Edition with latest updates, in English and with Making History DLC.

Thanks!