SMPlayer Support Forum

Ubuntu 18.04
Smplayer also 18.04
Long time user of SMplayer on previous Ubuntu versions.

When I select a video to play (no matter the video format), it opens in a second window. That window has no controls and is not resizable. Sometimes its very small; to small to view easily. To operate controls, I must select the SMplayer window (which is empty of video) which causes the window playing the video to hide. I must then select the second window again to see the playback. Want to skip forward? Change windows to do so, then again to see result. Smplayer is pretty unusable at this point. I've searched google, but nothing of consequence was found. Back to VLC? I really prefer SMPlayer but....

I think this usually happens when using Wayland instead of X11. Go to preferences -> general -> video and select a different video output.

Not using Wayland, but your response did lead to discovery that the issue was that mpv was selected in preferences and that was the second window opening. The other option was mplayer, but errors in trying to use that led to discovery that mplayer was not installed!!!!! WTF Installed mplayer and SMplayer now works like I'm used to, which is great.

/rant on
Ubuntu 18.04 is the worst Ubuntu upgrade I've ever experienced. I'm 0 for three on upgrading computers that were running 17.10 without major hassles including having to wipe and re-install Ubuntu 18.04 multiple times. One computer still will not boot after fresh install of 18.04; probably go back to either 16 or 17 (which ran fine). Heck, why not Mint -- brilliant.
/rant off.