Undefined index

[@rjen]

Go to the category settings, switch ON the setting show subcategories and save it. Errors will be gone.
It seems the variable is not set on install...

Thanks @rjen, yep switched on "Display any child categories?" and indeed the errors stopped. 

It actually should not matter what setting you change: it is caused by the variable missing when a new cat is created. Same happens when you create a new cat and not make ANY changes to the settings. Then create a child cat and it happens too...

[@rjen]

Attached file fixed it...

[@rjen]

Nice, same issue in 2.0.0... I'll fix that too...

[Lesmond]

 

Go to the category settings, switch ON the setting show subcategories and save it. Errors will be gone.
It seems the variable is not set on install...

Thanks mate fixed it for me too, 

[@rjen]

One thing also noticed, but unrelated.  While trying to replicate this I deleted the sub cat name and saved, there was no way to get back to that category to edit it afterwards, even though it's obviously still there. So that's another issue.  Probably needs some sort of default value.

That is no longer an issue in 2.0.0: I did already add the 'Edit' icon on the reworked category layout as well. I could do the same in 1.6.x, but we agreed the 1.6 would be a bug-fix branch only, and this is not a bug, more of an 'unrequested-feature'..

[@rjen]

This actually makes me wonder: why do we even allow users to create articles and categories WITHOUT a name? Is that something that has a reason? Or is that because in the olden days no one thought to make the names required entry fields?

I am thinking to do that (make them required) to prevent such things from happening at all...

[lurkalot]

This actually makes me wonder: why do we even allow users to create articles and categories WITHOUT a name? Is that something that has a reason? Or is that because in the olden days no one thought to make the names required entry fields?

I am thinking to do that (make them required) to prevent such things from happening at all...

I wondered that too, hence why I said they should have some sort of default value, or it should prevent you from saving it without entering something.

[@rjen]

I noticed that I creates a default value when you create a new category without a name (-no name-), but it lets you delete it completely afterwards...

On articles something similar happens, but that seems to be more completely implemented.
I guess for categories it should be mandatory to specify a name at all times. What about articles?

[lurkalot]

I noticed that I creates a default value when you create a new category without a name (-no name-), but it lets you delete it completely afterwards...

On articles something similar happens, but that seems to be more completely implemented.
I guess for categories it should be mandatory to specify a name at all times. What about articles?

Or blocks. 

[@rjen]

I noticed that I creates a default value when you create a new category without a name (-no name-), but it lets you delete it completely afterwards...

On articles something similar happens, but that seems to be more completely implemented.
I guess for categories it should be mandatory to specify a name at all times. What about articles?

Or blocks. 

That's not an answer, but another question  ...
So what do you think / want there?