1, the file format is wrong. When downloading e-books, you should pay attention to choosing common formats that meet the standards and specifications to ensure compatibility.
2. The file is damaged. E-book files are damaged for various reasons (such as incorrect download and incomplete file transmission). ), which makes it impossible to open it when reading. In this case, you can try to download or repair the damaged file again.
3. Software problems. There may be some problems in the software itself, such as software failure or outdated version. Updating reading software will not solve the problem. You need to try to use another reader or reinstall the latest version of reading software.
4, mobile phone problems. There may be limitations or faults in the hardware or operating system of the mobile phone, which makes it impossible to import e-book files. In this case, you can try importing files on different devices or operating systems.