Ensure You Have As Much Data As You Might Have
The script shows its advance in the left up corner.
The temporary working chart runs in the background.
The offline chart indicators have ability to fetch data by itself, but the fetch is only effective for the last 512 to 2048 candles. If you like to get more, you can achieve it by other means, and this script is such a handy means.
The Load All History script is a free tool for those who need to ensure the best initial condition for the offline chart generators.
The script belongs to the Scripts folder. It is effective only to a symbol of the chart it has been dropped onto. It forces all the available timeframes data to download into the MT4 history pool.