I'm not sure if this is what you're experiencing or not, but we've encountered something similar where it appears the Modify Attributes window is not opening, after trying every method we can think of. I eventually discovered it was opening off-screen. Deleting the cache file or restarting multiple times worked sometimes, but we've had better success with the following method.
NOTE: After opening the Modify Attributes window, make sure you don't click anywhere with your mouse, or this will not work.
When the modify attributes window is open but not visible:
1. Hold [shift]+[alt]+[space] on your keyboard. This opens up a menu on the active window, which may or may not be visible on screen.
2. Press [M] on your keyboard. This selects the Move option, and snaps your mouse to the active window.
3. Click and drag the window onto the screen,
OR
Press any of the arrow keys on your keyboard, then move your mouse without clicking to drag the window onto your screen.
Hopefully this helps. Again, I'm not sure if this is what you're experiencing, but it sounds like it might be, and this worked for us!
