Error when hiding a datatable column that's selected

I found a bug that’s present in Webix 4.0 upwards. When selection is enabled in a table and you select a row, the table remembers which column you clicked. When you use hideColumn() and showColumn() on that particular column, you will get an error.

The last version I tested with that does not have this bug is 3.3.17. Both 4.0 and 4.1 do have it, though.

I also created a snippet to demonstrate the issue. Steps to reproduce are on there as well.

Snippet: http://webix.com/snippet/757f7099

Thank you for reporting this issue, the fix will be included in the next version (4.2).