I get this error when attempting to install the 32bit ISO for the LTS Ubuntu 14.04.6 LTS (Trusty Tahr)
First determine if the ISO you downloaded is solid. There must be an SHA or MD5 checksum of it at the mirror where you downloaded it. You can find additional information on the thread here https://help.ubuntu.com/community/HowToSHA256SUM .
After that, if you trying to install the OS on a virtual machine, make sure you have enabled the Virtualization on your bios, although that should not be a problem since you are trying to install a 32bit version.
If you are installing through usb make sure the filesystem is FAT32 and create again the bootable media through a tool like UniversalUsbInstaller. Even better format the USB under the filesystem of FAT32, and later create the bootable media.