I am trying to update my os 10.11 in order to connect a new printer. Apparently this version is no longer supported? is there a work around? there is nothing wrong with my mac pro. I just needed a new printer

Hi,

Many newer printers do not have printer drivers for an old system like OS X 10.11 El Capitan. This, normally, means that USB connections will have to be ruled out.

If the printer is a network model (either Ethernet or Wi-Fi, or both), and is compatible with Apple's AirPrint technology (About AirPrint - Apple Support), it may be possible to use it with OS X 10.11 El Capitan. AirPrint as such could work with operating system versions as low as Mac OS X 10.7 Lion. However, the printer manufacturer may provide additional software (for example, for setup and ink-management purposes) with higher requirements.

Knowing the exact printer make and model would help us check available options.

It's hard to tell you much as you have not provided us with any useful information such as your Mac's year and model and what operating system it has installed. Apparently your printer's instructions for its driver is asking a certain version of OS or newer for the driver to work with. I would (1) try to upgrade the OS as suggested. Your Mac may or may not be able to accept the upgrade, however. (2) You can check the printer's web site to see if they have available an older driver that will work with your installed OS.