PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

If you are trying to upgrade, and suddenly start getting errors like:

Incompatible Archive. PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

Here are some things to check.

• This basically means that WordPress is not able to unzip the downloaded packages to install the upgrades.
• Check to see available space on your disk. If your disk is full you should try upgrading your hosting package or freeing up some space on the disk. One easy way might be to delete old image thumbnails in sizes you no longer use.
• If you have enough space on your disk, it may be that specific downloaded packages may be problematic. Try to install a plugin you don’t have, and if that works, you should check to see if there is a mysterious folder called “Upgrades” [DO NOT CONFUSE WITH UPLOADS]. If this folder exists, it is worth deleting it to see ii that lets  you do the upgrade.