Eleonora and Yuhang
Firstly, we found that all the filters disappeared in foton (as shown in the attached figure 1).
Then we tried to restart standalone computer. However, after that, k1fds stopped working (as shown in the attached figure 2).
At the same time, we found that by using command 'df', /dev/sda1 shows 100% used (as shown in the attahed figure 3).
Eleonora tried to ssh standalone, and used command 'lsmod', and found there was no k1fds. She tried command 'startk1fds'. But it didn't work (see attached figure 4).
So probably the problem is connected with the full of /dev/sda1.