With 5.4.2 , and before, here is the bug
https://snippet.webix.com/3j67oyp4
When clicking to button (active element), if datatable is selectable (row in my case), this.config.$masterId return null. If not selectable , his.config.$masterId return id.
Thanks to fix it 
Hello,
Please check the next snippet - it is the recommended approach for adding buttons into the rows of datatable.
http://webix.com/snippet/39dd5eaa
Yes i know. It’s what i have done.
But with Active Content, there is a bug
Same problem with Checkbox
https://snippet.webix.com/gewfex24
How do you resolve this problem ?
{common.checkbox()} doesn’t draw the good theme.
Active Content is great because you don’t have to draw controls yourself.
Please fix the bug.
Thanks
Checkbox in a datatable is a common use case, so it has its own shortcut common.checkbox()