Two PHP errors

I. Fatal error: Call to undefined function: iconv () in c: \ Program Files \ appserv \ www \... \ XXX. php on line 82
PHP has an iconv () function for character encoding conversion.
The extension = php_iconv.dll also exists in the PHP. ini file.
This declaration ensures the normal use of this function.
If there is a semicolon before extension = php_iconv.dll in the PHP. ini file
It indicates that it has been commented out. If there is a semicolon, remove it and restart the server.
You can solve this problem by running the program again.

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Ii. Fatal error: Call to undefined function: mb_detect_encoding () in c: \ Program Files \ appserv \ www \... \ XXX. php on line 1355
1. Find the PHP extension directory (the path of my PHP extension directory is: C: \ Program Files \ appserv \ PHP \ extensions)
Find the php_mbstring.dll file under the extensions directory,
2. Copy the php_mbstring.dll file to the directory where the php. ini file is located (the directory where the php. ini file is located: C: \ Windows)
3. Open the php. ini file in notepad and press Ctrl + F to find extension = php_mbstring.dll.
4. If the php. ini file contains extension = php_mbstring.dll, remove the semicolon before the extension line,
If it does not exist, add extension = php_mbstring.dll to the next line of other extension =,
Remember to save the php. ini file.
5. Restart your Apache server

I just found that the file php_mbstring.dll is not copied to the directory where PHP. INI is located.