WordPress Admin Dashboard Pages 404: Page Not Found

Hi everyone. I hope I can find solution here. I have a problem on my WordPress Admin Dashboard. I can log in on my Admin dashboard but when I click any items (for example the settings), I’m getting 404: Page Not Found.. The weird thing is, I can open some plugins installed (for example, Sucuri) but unfortunately, I cannot open the Plugins Tab itself. I cannot also open the Updraftplus. Anyone know this problem? Thanks.