https://devzone.nordicsemi.com/f/nordic-q-a/25772/i-have-alot-of-error-with-keil-5-06-can-anyone-help-me*** Using Compiler &#39;V5.06 update 5 (build 528)&#39;, folder: &#39;C:\Keil_v5\ARM\ARMCC\Bin&#39; Build target &#39;nrf51422_xxac&#39; compiling main.c... ..\..\..\..\..\..\components\drivers_nrf\hal\nrf_gpio.h(67): error: #35: #error directive: &quot;Not supported.&quot; #erroren-USTelligent Community 13Mon, 09 Oct 2017 08:22:42 GMThttps://devzone.nordicsemi.com/thread/101530?ContentTypeID=1Mon, 09 Oct 2017 08:22:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2a6b5d6e-a597-46b3-9303-1fe17aed9fb8J&#248;rgen Holmefjord<p>The first error indicates that the symbol GPIO_COUNT is not defined. This should be defined in the file <em>nrf5xxxx_peripherals.h</em>, found in <code>\components\device\</code>. This correct file should be included by the file <em>nrf_peripherals.h</em> in <code>\components\drivers_nrf\hal</code>, based on the device defined in the preprocessor symbols. Which SDK version are you using? Are you basing this on a SDK example?</p><div style="clear:both;"></div>