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I have a problem that when I select certain addons that require parameter changes, I'm not able to edit them, they appear greyed out.
I assume this is a system settings problem (since it happens across versions) and experience something similar when, for example, adding a circle. I resolved this by changing "new objects enter into edit mode" in the "editing" settings.
Unfortunately even though this setting works for objects it doesn't work for things like the "fracture","ANT", "Sapling etc. Any ideas?