Photoshop issue: Annoying red screen while typing. Not Quick Mask-related. Easy solution.
Many of those who respond to technical support requests in Adobe forums seem to think that they know everything, and that this annoying red screen while typing MUST be related to Quick Mask mode, hardware acceleration, or use of the wrong text tool. This is not always true. It will also occur if the 8-bit indexed color setting is used, as this mode does not allow for the creation of new layers (even text layers).
The solution is to change "Mode", under the "Image" dropdown, to RGB color with 16 or 32 bits per channel. Other mode settings may also work.