Missing required active authority: Missing Active Authority | WHY?

Hello steemians ...
In this posting I just want to share my problem when I want to remove power delegation on my account and then when I input my passwords just notify me missing required active authority: Missing Active Authority. and I don't know why it happen, I just looking for some article but I don't get it, so anyone can help me to fix this problem???

So, I will Steemians could help me fix this problem, and if you know this problem and know how to fix it, please tell me !!