Seems I discovered a bug in the new 5.4 firmware yesterday. The behavior is that a single-buffered roScreen has 50/50 chance of showing on screen - and when it does not show, program does not exit abruptly; everything works smooth - except roScreen is not visible, instead the "Loading..." poster stays there. I think this is 5.4-related because it happens on HDMI Stick and also on 3100 player with 5.4 - but not on Roku3 with 5.3. When i noticed it, I tested by launching the code 10 times one after another, ECP or remote - and in half the cases roScreen shows up, in the rest it does not; there was no particular pattern (e.g. not "every other time").
Here is the code
viewtopic.php?f=34&t=64834#p437652 - followed by discussion with TheEndless, who - much obliged! - vetted it on his device, noted it does not happen with double-buffered roScreen and came with the theory that it depends on when (i.e. in which buffer) the loading screen got interrupted by the creation of roScreen. Great thinking! Seems to me a very likely explanation.
Severity: if this is indeed 5.4-related behavior, it may mean channels built on single-buffered roScreen will have 50% chance of meatballs - i mean seemingly not working. Repeating the start once or twice more will work.