phpmyadmin - Fatal error : allowed memory size of bytes exhausted

Fatal error: Allowed memory size of bytes exhausted (tried to allocate bytes)

If you are not able to open phpmyadmin because of this error, follow the steps to remove it.

1) Open file php.ini
xampp : /opt/lampp/etc/php.ini
apache2 (Debian) : /etc/php5/apache2/php.ini 
httpd (RHEL) : /etc/php.ini

2) Search parameter memory_limit. By default it's value is 128M.

    Increase the value according to size of parameters upload_max_filesize and post_max_size.

memory_limit = 512M

3) Restart Apache.

There is a instruction in php.ini that "Maximum amount of memory a script may consume (128MB)" but when you will increase the memory size greater than 128M, you will see yourself that error is gone.


NOTE :
The first things to check are the values of upload_max_filesize, memory_limit and post_max_size in the php.ini configuration file. All of these three settings limit the maximum size of data that can be submitted and handled by PHP. post_max_size and memory_limit need to be equal or larger than upload_max_filesize.

Be careful to set memory_limit size. If it exceeds the limit, the phpmyadmin does not start. It shows blank page.

You have increased the memory limit but you still get this error frequently. Restart the Apache will solve your problem. If you are working on live Linux server and it does not restart frequently. You might get this error too often, make a Crontab for daily Apache-Restart will solve your problem.

ERROR 2006 (HY000) at line ##: MySQL server has gone away

 MySQL server has gone away : Error while uploading sql file in phpmyadmin

1) Open file my.cnf 
xampp : /opt/lampp/etc/my.cnf
apache2 (Debian) : /etc/mysql/my.cnf 
httpd (RHEL, CentOS) : /etc/my.cnf

2) Set value max_allowed_packet=128M under attribute [mysqld] 
    If parameter is not there, add it under attribute [mysqld] .

[mysqld]
max_allowed_packet=128M

3) Restart mysql.

Access forbidden : New XAMPP security concept : XAMPP - phpmyadmin error

Solution :
Access forbidden :  New XAMPP security concept error in phpmyadmin after new XAMPP installation

1) Open the file /opt/lampp/etc/extra/httpd-xampp.conf

2) Search text #New XAMPP security concept in the file and replace Deny from all to Allow from all under #New XAMPP security concept

3) Add line Require all granted in <Directory "/opt/lampp/phpmyadmin">. 
 Now it looks like this.

<Directory "/opt/lampp/phpmyadmin">
    AllowOverride AuthConfig Limit
    Require all granted
    Order allow,deny
    Allow from all    
</Directory>

4) Restart XAMPP

If you are still getting problem

Solution : 2
Run following command

$ sudo /opt/lampp/lampp security

Set password for everything.
Restart XAMPP and try again.