[Superset]: 500 - Internal Server Error from List Slicer windows

[mariaclaudia]

Subject of the issue

Error 500 when you click on column names to order by Slice | Visualization Type | Datasource | Creator

Your environment

Chrome

Steps to reproduce

1_ Go to Superset
2_ Click on "Slicer" on the top bar
3_ Click on the column names (Slice | Visualization Type | Datasource | Creator) in order to order by the selected field

### Expected behaviour The list should be ordered by the selected field.

Actual behaviour

500 - Internal Server Error
Please see the screenshot attached.

[michelepetito]

Hello!

The problem occurs to me only for "Slice" and "Creator" columns. The sorts "Visualization Type" and "Datasource" work for me.

I'm using Chrome version 64.0.3282.186 (64 bit) on Mac OS v. 10.12.6.