This bugs took me 2 hours to find the caused.
I’ve an article origin title is “Flask xhtml2pdf with images“. Nothing special, but when I create a page and link to this post, It always complain Server Error 404. I’ve check the memory and others mention solution. It seen like not related at all. After few tried to modified to origin content, I finally spot that the input text fields cannot contains “xhtml” this words. I’ve to rename my article to “Flask x-html2pdf with images” and edit the link to “http://codeomitted.com/flask-x-html-2pdf-images“