Account and server
An MT5 account will not authorise on an MT4 terminal and vice versa. Check the platform label in your client area, then use the matching terminal and server name.
Instrument coverage
MT5 typically exposes a wider instrument list, particularly share and index CFDs. If an instrument is missing from market watch, use the symbol browser to add it rather than assuming it is unavailable.
Workspace setup
Enable the economic calendar tab, set the market watch to show spread as a column, and save a profile per instrument class so switching context takes one click.