Not found URI: / Method: GET Error

Hi, 
I have compiled the code for a Wemos D1 Mini Board and connected all like the schematic.
After startup, on the serial Monitor I see:
Connected to WLAN01234
IP address: 192.168.1.226
RSSI: -63
Mode: 3
WebDAV server started

I get the Error "Not found URI: / Method: GET" on the Webpage 

What's wrong?
Thanks, regards Roland