Following the tutorial from youtube, after creating the skeleton, you need to switch to the weight painting mode.
It seems to me that I do everything exactly the same as the author, however, I can't select a bone using ctrl+left click. 
Please tell me what could be the problem?

[<img src="https://blend-exchange.com/embedImage.png?bid=mo270e28" />](https://blend-exchange.com/b/mo270e28/)


[![weight painting][1]][1]


 [1]: https://i.sstatic.net/fzHyH5Y6.png