1: Action bar missing/Won’t load:
—Solution: Change interface around, click the little – at the bottom of the screen, and or try the Java download’s client.
2: massive Lag:
—Solution: Try the Client-Downloadable.
—Switch to Old School Interface, which is quite small. And annoying. But less lag.
3: Black Screen of Jagex’ed
—Solution: Clear Jagex Cache, reinstall/Install Client, mess with interface settings and or wait 5-15 minutes. Do not ALT Tab out to other screens. This can make a Black Screen occur and or last longer.
4: Keybinds will not work:
—ALT TAb out and then back in, and try again. It seems to work, though it may cause the “Black screen of Jagex”-Trademark, MMG-2013. -Bringing quality gaming to Runescape Gold since Andrew left.
5: Chat(Friends, Global etc: Whenever I talk, or whenever anyone talks, I have to scroll down to see, and it will not auto keep up with the convo.
—Solution: Try a difference interface, or even enlarge the Chat box. Or shrink it. Messing around seems to fix it. AS well as logging out/In.
6: Glitchy Graphics:
—Solution: DO not use the HTML5 Beta. Use Java. If still using Java, then change interface or clear Cache.
7: Cannot connect to game server with DL Client:
—Solution: Reinstall, Clear Cache, and or try a few times in a row. If still not work, then try again.

Notes:
The DL client usually has a lot more FPS and a lot less lag, net wise and FPS wise. The Browser client has also been found to be more unstable, Black Jagex’ed prone, and more prone to having sound problems.