phpMyAdmin error: Error in processing request

Symptoms

When accessing phpMyAdmin, the below errors appear.

Error in processing request
Error code: 200
Error text: OK (rejected)
It seems that the connection to server has been lost. 
Please check your network connectivity and server status.

Description 

cPanel stores temporary data for phpMyAdmin. If this data becomes corrupted, it can cause errors in the phpMyAdmin interface. Many scenarios exist in which this data could rarely become corrupted. In the rare instance the issue occurs, it would be required to re-create the temporary data. Accessing the phpMyAdmin will create this data automatically if missing.

Workaround

1. Move the existing phpMyAdmin tmp data, then login to a new phpMyAdmin session. Access the SSH or File Manager to move the path below to a backup or a new name.

• /home/$cpanelusername/tmp/pma_template_compiles_$cpanelusername

For example, you would perform the below command in SSH, terminal, or a shell.

Note: Replace $cpanelusername with the cPanel account user name experiencing the issue.

mv -v /home/$cpanelusername/tmp/pma_template_compiles_$cpanelusername{,.cPbak}

2. Next, try accessing phpMyAdmin from a new cPanel login or re-login to the same account.