# Error when testing the Arduino Example?

**URL:** <https://discourse.mozilla.org/t/error-when-testing-the-arduino-example/47566>\
**Category:** WebThings\
**Created:** [October 28, 2019, 8:53am UTC](https://discourse.mozilla.org/t/error-when-testing-the-arduino-example/47566 "2019-10-28T08:53:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dbunting](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/dbunting/32/31213_2.png) [@dbunting](https://discourse.mozilla.org/u/dbunting)\
**Post date:** [October 28, 2019, 8:53am UTC](https://discourse.mozilla.org/t/error-when-testing-the-arduino-example/47566/1 "2019-10-28T08:53:48Z")

</div>

Fairly new to WebThings.  
I tried searching the borad for this first but didnt seem to hit upon anything.

I am trying to use JUST the example code as found on [https://iot.mozilla.org/framework/](https://iot.mozilla.org/framework/)  
I have added the webthing library to my arduino IDE libraries, and ArduinoJson was already there from prior projects, and it is up to date.

I copied and pasted the example code from [https://iot.mozilla.org/framework/](https://iot.mozilla.org/framework/) into the IDE, entered a SSID and Password, saved it, clicked verify, and to my shock and horror saw a compilation error.

```
In file included from 
C:\Users\ME\Documents\Arduino\sketch_oct28a\sketch_oct28a.ino:1:0:

C:\Users\ME\Documents\Arduino\libraries\webthing-arduino/Thing.h:16:31: fatal 
error: ESPAsyncWebServer.h: No such file or directory

#include <ESPAsyncWebServer.h>

                               ^

compilation terminated.

exit status 1
Error compiling for board LOLIN(WEMOS) D1 R2 & mini.

```

Is there something OTHER then the Webthing and ArduinoJson libraries that I should have downloaded that wasnt mentioned in the [https://iot.mozilla.org/framework/](https://iot.mozilla.org/framework/) page?

The **framework** page identifies **webthing-arduino** is for PlatformIO and **webthing** is for ArduinoIDE. However when I went to add the library to ArduinoIDE the only result was for **webthing-arduino** which I installed (version 0.9.0).  
Have the 2 libraries been merged?  
Did I add the wrong library?  
Should I uninstall and ALT+F4 life?

Thanks in advance

---

<div class="post-metadata">

**Author:** ![mstegeman](https://avatars.discourse-cdn.com/v4/letter/m/b782af/32.png) [@mstegeman](https://discourse.mozilla.org/u/mstegeman)\
**Post date:** [October 28, 2019, 4:24pm UTC](https://discourse.mozilla.org/t/error-when-testing-the-arduino-example/47566/2 "2019-10-28T16:24:33Z")

</div>

Per the [README](https://github.com/mozilla-iot/webthing-arduino#readme):

> You will also need to download the [ESP Async WebServer](https://github.com/me-no-dev/ESPAsyncWebServer/) library and unpack it in your sketchbook’s libraries folder.