Why is the xmind mind map on Huawei's tablet missing?

The reason why xmind's mind map on Huawei tablet disappeared and its solution;

1, not saved, resulting in all empty when exiting.

2. Create a new folder in xmind, create a file in the new folder that occupies the name (it is in other folders, so it will not be occupied), and then move this file back to the main folder (that is, the folder where the files are missing). There will be conflict at this time.

3. Replace the original file or keep it or stop it. Select the replace option, and you will find that it was recently deleted.