Error when Export grid to Pdf

When I try to export a grid in production mode, it tells me that it cannot find the pdf file. The .log say: ./wkhtmltopdf-amd64 --page-size Letter --orientation Portrait --header-right “[page]” --javascript-delay 2000 /home/user/ both files are in tmp. and the bowser say: [h=1]Not Found[/h]
The requested URL was not found on this server. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. Please, take a minute and help me… thank you