Or, just possibly, almost every time I try using Mega from the browser, it tells me game files are to large and I need to use the app.
are you using some kind of device that is designed for telephoning your mother on a sunday night?or are you using a device designed to play "computer" games?
even if its some kinda weird computer, cause is given to you right there - not using the right tool for the job. get a better browser, one that is capable of doing the job you require of it.
sounds like user error to me.