Photoshop brush tip at both ends of a sudden gone Why

Some people see that there have been with me the same question but has not been resolved quoted

about photoshop, I have two of those tip of the brush default of a sudden disappeared into the rough in the end the kind of start from scratch, There is no way to draw a line change.Some people say that there is a tablet that brush, is making irresponsible remarks.I did not buy a tablet when there was a brush, so I designed that the most commonly used pen Brush, and later bought a tablet, again using the brush to draw the line there are more delicate.But all of a sudden today, the two sharp did not brush there will be no default, the Internet is absolutely no, but then I had re – PS, or even no! ! I also re-drive the tablet is also Wuyong Gong.Expert advice, please, how to restore those default brush! ! (Reset brush is of no use, following the reduction or about the same as that of the rough brush.But also in the pre-brush is not sharp at both ends of the brush, it would not be included in the brush line.

cong zuang yi xia xi tong