If you use CoolReader on a M92 please try this:
Create an empty file.oar and write these simples command inside it
Code:
#!/bin/sh
du -d 1 -h /root/.cr3/ >> $0.size.txt
ls -latr /root/.cr3/cache/ >> $0.list.txt
and put this file in the SD (the root o an any folder) then execute it with OK button (or select it with the stylus)
Two new files are created in the same folder. This file contains the size of the /root/.cr3/cache/ directory (size.txt) and, if exists, the list of the epubs opened (list.txt)
I don't want to infringe your privacy and don't want to know the content of the second file (list.txt) but I want to know if also (you who have a recent version of the firmware) your CoolReader stores each epubs opened.
If you can please report also the exactly version of your firmware