Hello Basic forum,
I am new in this forum as well as with ESP8266. I had exactly the same problem as discussed in this post.
Yesterday I found the final hint in another post
viewtopic.php?f=45&t=10368&start=16 [/b] by PeterN.
The problem seems connected to the chip vendor. I have 2 WeMos D1 Mini labeled with HYSIRY which means Shenzhen Hysiry Technology Co., Ltd.
Before I used ESP_Basic_Flasher and esptool / flash.cmd from ESPEasy which both are loading other firmware without problems. After flashing the 4MB ESPBasic with NODEMCU FIRMWARE programmer ESP8266Flasher.exe my boards are working perfectly.
When the board is loaded correctly the LED flashes a second time approx 30 sec. after reset !