I keep getting an error when uploading a project “1.2-Hello World Web Server” (from the Build WebServers eBook-2nd edition).
I followed all the instructions carefully:
-using ESP32 DOIT DevKit v1
-using PlatformIO on VSCode
the error is:
c:/users/izmai/.platformio/packages/toolchain-xtensa-esp32/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: .pio\build\esp32doit-devkit-v1\libabc\libESP Async WebServer.a(WebAuthentication.cpp.o):(.literal._ZL6getMD5PhtPc+0x4): undefined reference to `mbedtls_md5_starts’
c:/users/izmai/.platformio/packages/toolchain-xtensa-esp32/bin/../lib/gcc/xtensa-esp32-elf/8.4.0/../../../../xtensa-esp32-elf/bin/ld.exe: .pio\build\esp32doit-devkit-v1\libabc\libESP Async WebServer.a(WebAuthentication.cpp.o): in function `getMD5(unsigned char*, unsigned short, char*)’:
C:\Users\izmai\Documents\PlatformIO\Projects\test_filesystem_webserver/.pio/libdeps/esp32doit-devkit-v1/ESP Async WebServer/src/WebAuthentication.cpp:73: undefined reference to `mbedtls_md5_starts’
collect2.exe: error: ld returned 1 exit status
*** [.pio\build\esp32doit-devkit-v1\firmware.elf] Error 1
 
PS: The previous example worked fine.