Database errors can be annoying especially when doing last-minute updates.

Usually, this MySQL error token mismatch pops up in database management tools like phpMyAdmin. The major reasons include insufficient disk space, incorrect permissions and many more.

At Bobcares, we receive requests to fix the MySQL errors as a part of our Server Management Services.

Today, let’s know the causes of this token error and see how our Support Engineers fix it in MySQL.

How does MySQL error token mismatch show up?

MySQL databases of websites need periodic editing. And, tools like PHPMyAdmin make things pretty simple.

PHPMyAdmin makes use of session cookies to maintain the connectivity between the browser and the database server.

However, due to various reasons, there can be a colliding session cookie present in the browser. As a result, PHPMyAdmin shows up the Error: Token mismatch. Also, this error can pop up while opening the phpMyAdmin tool or while trying to import or export the database.

Causes of MySQL error token mismatch and how we fix it?

Let’s now check into the various reasons that cause the token error in MySQL. We’ll also see how our Support Engineers fix it.

1. Disk Quota

The disk space of the server plays a major role in creating errors in the account. Likely, this error token mismatch can cause due to the disk space of the server being full.

Also, the error can pop up if the /tmp directory is full.

Recently, one of our customers approached us with a token mismatch error in phpMyAdmin.

Our Support Engineers started troubleshooting this error by checking the disk space on the server using the command

df -h

Here, we could make out that the /tmp folder was full.

Filesystem     Size     Used   Avail   Use%      Mounted on

/dev/sda1      75G      23G    49G     100%       /tmp

So, we removed the unwanted files from the server. And also cleared the /tmp folder.

Finally, this fixed the error and the customer was able to connect to phpMyAdmin.

2. Incorrect permissions

In a similar way, incorrect permissions also cause MySQL error.

The permissions of the folder /tmp must be set to 755. In case if there is any alteration made in the permissions then the database will throw an error. We can update the permissions of the /tmp folder using the command:

chmod 755 /home/username/tmp

3. session.save_path in php.ini

The /tmp folder stores all the sessions. So the value of session.save_path must be set as /tmp. Sometimes, this line in the php.ini file will be commented on. This creates problems with MySQL database management.

In such cases, we can uncomment it and set the value to /tmp.

session.save_path = "/tmp"

And then, we can restart the apache using the command.

service httpd restart

4. Browser cache

A cached browser cookie can also cause this error.

In such cases, we quickly access the PHPMyAdmin in some other browser and test if it works. If the error disappears, then we suggest customer to simply clear the browser cache and cookies. This usually helps in fixing this error.

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Conclusion

In short, the MySQL error token mismatch is mainly caused either due to the disk quota being full, or incorrect permissions or by not setting the session storage path in the php.ini file. Today, we discussed the error token mismatch and how our Dedicated Engineers fix it.