# Sorry! File "`__MD_PLACEHOLDER__`" is not available. It is either not found in the current directory or could not be opened. Local HTML file cannot access the markdown file (or any other files in the same directory) in modern browsers due to security reasons. This was possible in Firefox versions below 68. There are now two methods to handle this: ## The secure method: HTTP server setup Run a minimal HTTP server: * Using node: * Install [node](https://nodejs.org). * Install `http-server` by running "`npm install -g http-server`". * Start the HTTP server by executing "`http-server -p 8000`" in the directory of markdown viewer. * Using python: * Install [python 3](https://www.python.org/). * Start the HTTP server by executing "`python -m http.server 8000`" in the directory of markdown viewer. Then, open the markdown viewer HTML file using URL "`http://localhost:8000/__DOC_NAME_PLACEHOLDER__.html`". You can replace 8000 with other available port numbers. Note that a port number cannot be used more than once simultaneously in different servers. If it is not pleasant to run multiple HTTP servers with separate port numbers for rendering different markdown files in several directories, you can run the HTTP server in a common parent directory, and open the markdown viewer files with relative addresses, e.g. "`http://localhost:8000/common/parent/path/to/__DOC_NAME_PLACEHOLDER__.html`". You can also use browser extensions like [Web Server for Chrome](https://chrome.google.com/webstore/detail/web-server-for-chrome/ofhbbkphhbklhfoeikjpcbhemlocgigb). ## The insecure method: Allow accessing local files ** Warning: ** This method makes you vulnerable to attacks from downloaded HTML documents. ** Firefox: ** Open "`about:config`" and accept the risk to edit the configurations. Search for "`privacy.file_unique_origin`" and set its value to `false`. Other work-around ideas are welcome. Contact through the issues in [the development repository](https://github.com/ioi-2017/markdown-viewer/).