Just FYI as someone who use to do what you describe here I know the pain
you are experiencing trying to download historical data.
There is a better/easier way to get the data from the server from your broker and that is:
Step 1: Open an M1 chart
Step 2: Go to History Center (press F2)
Step 3: Navigate to the currency pair and the "1 Minute (M1)" history
data for the chart you have open in your terminal (be sure to "double
click" the "1 Minute (M1)" selection in history center so it actually
becomes the active selection)
Step 4: Then left click once on any of the data rows in the right hand
window of the History Center (it doesn't matter which one)
Step 5: Click the "Edit" button, this pops up another window titled "Bar" and the default selection is on the "year"
Step 6: Push the down arrow on your keyboard until the year reads something silly like 1970
Step 7: Then select "OK"...this doesn't actually edit the data you
selected but rather it creates a new bar with the timestamp and price
info you just edited...don't worry about this as you will delete this
fake bar in the end
Step 8: Now select "Close" in the History Center
Step 9: Navigate to your M1 chart of interest and then from the terminal
menu select "Charts -> Refresh"...this will refresh the chart and
attempts to fill any time gaps in the chart data (which now includes
your year 1970 data point) with server data
Step 9 continued...Now your chart will have pulled anywhere from 2048 to
65536 M1 bars from your broker's server (not Metaquotes server) and is
usually far more data than you can get the broker to cough up when you
try and manually scroll your M1 chart back in time
Step 10: Go back to History Center (press F2) and navigate to your currency pair and its M1 data
Step 11: scroll down the data to the bottom of the list, your will see
your 1970 candle there, click it once and then click the "Delete" button
in the History Center window
Now you have really quickly downloaded all the broker's M1 data on your
currency pair that the broker is going to let you have, much faster than
holding down the home or pg-up key for minutes and minutes to download
even less data. It works with charts of other timeframes as well.
Anything like that for 2018? taken from https://www.mql5.com/en/forum/124619#edit_form
I don't even want to know what the standard/more difficult way would be. Anyways, I did never experience problems with historic data with MT5. I don't know MT4.
1) Your data can only go back as far as your brokers data (MT5).
2) You may not see all the history because your charts are limited by "max bars in chart" setting in the options menu.