I can't recall if this always happened or not:
When editing a particularly long line enough to require that the scrolling code area be widened, it doesn't automatically re-adjust itself. In other words, if you add a bunch of text to the line you cannot scroll far enough to the right to see the entire line. Also, it doesn't automatically scroll horizontally so you end up typing blind.
The way I have found to fix it is to slightly adjust the overall width of the entire IDE window which resets the scroll bar.
When editing a particularly long line enough to require that the scrolling code area be widened, it doesn't automatically re-adjust itself. In other words, if you add a bunch of text to the line you cannot scroll far enough to the right to see the entire line. Also, it doesn't automatically scroll horizontally so you end up typing blind.
The way I have found to fix it is to slightly adjust the overall width of the entire IDE window which resets the scroll bar.