I have read a previous thread regarding the issue of "Internet download failed because content size exceeds system memory limit".  It appears to remain unresolved, however.  It occurred first yesterday for me.  I had no previous experience of the problem.  I could not put a finger on it, either: first, a one-hour programme would not play, while a half-hour programme seemed OK.  I went to a one-hour programme from last Saturday that my wife had watched and that was OK.  Returning to it later, the message appeared.  I assume repeated playing, or attempts to play, do not accumulate to cause a memory problem.

I have a problem with my Sony DVD recorder, too, regarding "D---" that has occurred recently, too, about which I shall create another post.

My TV is Sony KDL-32W705BBU, purchased in 2014 and my DVD recorder is Sony RDR-HXD870, purchased in 2007.