Hello everyone.
I use " WebServer_ESP32_W5500" library (WebClient) for my project ESP32 + W5500.
I select "Board: ESP32 dev module" in menu.
It used to work ok before reinstall Windows OS. Now it does not. Error:
esp32_w5500.h:80:5: error: 'IPv6Address' does not name a type; did you mean 'IPAddress'?
** 80 | IPv6Address localIPv6();**
I tried to run example of that library but not successfully (errors again).
How can I fix it?
Thank you.
with esp32 platform version 3, use my EthernetESP32 library with the esp32 WebServer. see the HelloServer example
Thx for reply Juraj. So whats wrong with WebServer_ESP32_W5500 library? it worked good before.
I use WebClient.
as @Juraj indicates it is probably a problem with Migration from ESP32 Arduino Core 2.x to 3.0
many programs/libraries which worked without problems with V2.x need updating to work with V3
as an interim solution you could install a V2 core but then new code implemented for V3 may not compile
Probably u r right.
Its really 
Thx guys for advice. 
