Hello, it doesn’t necessarily mean that it’s not compiling. Can you post the full error message that is being printed in the Arduino IDE? If you have multiple libraries, you might need to follow the path that is printed in the serial monitor to delete the  duplicate libraries.
Regards,
Rui

Arduino: 1.8.9 (Windows 10), Board: “DOIT ESP32 DEVKIT V1, 80MHz, 115200, None”
Multiple libraries were found for “WiFi.h”
In file included from C:\Users\jack\Documents\Arduino\Asynch_Temp_Humid\Asynch_Temp_Humid.ino:8:0:
Used: C:\Users\jack\AppData\Local\Arduino15\packages\esp32\hardware\esp32\1.0.1\libraries\WiFi
C:\Users\jack\Documents\Arduino\libraries\ESPAsyncWebServer\src/ESPAsyncWebServer.h:33:22: fatal error: AsyncTCP.h: No such file or directory
Not used: C:\Program Files (x86)\Arduino\libraries\WiFi
compilation terminated.
Multiple libraries were found for “ESPAsyncWebServer.h”
Used: C:\Users\jack\Documents\Arduino\libraries\ESPAsyncWebServer
Not used: C:\Users\jack\Documents\Arduino\libraries\AsyncTCP
exit status 1
Error compiling for board DOIT ESP32 DEVKIT V1.
This report would have more information with
“Show verbose output during compilation”
option enabled in File -> Preferences.

However, I reinstalled Arduino and that eliminated the issue, although I’m uncertain what happened.  Now I cannot obtain my IP though it worked with previous builds where a server address was requested (I just confirmed with the relay web server lesson). It continues to state “Connecting to WiFi..”.

(Also, I noticed the code shows #include “DHT.h” yet the instructions state to name it “DHT_sensor”. )

(Also, note here the first link to download the AsyncTCP library goes to github where I downloaded it, but the second reference to it auto downloads the ESPAsyncWebServer library.

Installing the Async TCP Library for ESP32

The ESPAsyncWebServer library requires the AsyncTCP library to work. Follow the next steps to install that library:

1. Click here to download the AsyncTCP library )

(Also, how do you insert an image here?   I tried various formats with the image tool without luck.)

– Jack

Do you have an installation of Arduino in your computer or are you using a portable installation?

Windows 10 Arduino IDE on my desktop PC. 

Ok, if you’re using the Arduino IDE actually installed in your computer (no the portable version), you just have the libraries installed at My Computer > User > your_user > Arduino > libraries. Before installing any library, double-check that the library is not already there with a slightly different folder name, for example…