Many friends have blank front and backends after upgrading destoon. The reason is usually there is a problem with the write permission of the file, mostly cache or file. The test did not consider security issues. Just set all files to be writable. Solved.
Therefore, it is recommended to check the file permissions in the same way as the installation file when upgrading the upgrade package, otherwise you will encounter strange problems.
chmod -R 777 /public_html
The interface can come out, but then I found a prompt in the background that license.txt cannot be modified or deleted. Please check. For this problem, change the transmission mode of the FTP software to binary and upload license.txt.
For the first-time installation background that cannot be opened and is completely blank, it is usually because the folder or file permissions are not set properly, such as the lack of user group permissions for "IUST_your machine name" or its write permissions. , set it up and reinstall it.