ESP8266 version 2.5.2 versus version 2.4.2

[JRAlvarez2017]

I have several applications using ESP8266 libraries like ESP8266WiFi, ESP8266WebServer, and WebSocketsServer, and all of them work very well with the ESP8266 version 2.4.2. However if I update to version 2.5.2 none of them work. All with the same problem: the phone (or other ESP8266 in STA mode) is no capable to connect to the ESP8266 WiFi AP.
Are there unsolved WiFi connectivity issues with the version 2.5.2?

[Jason2866]

No

[Jason2866]

[JAndrassy]

@JRAlvarez2017, what are your Tools menu settings?

[JRAlvarez2017]

I normally use the board WEMOS D1 R2 & mini. With the Generic board and the suggested settings it is does not start.
Using the WEMOS board setup and your suggested settings, most of the applications work. There is only one with these libraries that works with 2.4.2, and does not work with any of the settings options of 2.5.2.

However the WiFi starting code seems to work, I will investigate more with the MCU is reseting.
Is there any place where I can learn about the meaning of each IwIP options?
Thanks for your help.

[d-a-v]

Did you try the third flash option "Erase all flash" (once) ?
With generic board and wemos d1 mini you must set 4MB flash size.

[JRAlvarez2017]

I just tried: Generic module, Erase all Flash, and 4MB flash size, but it does not start.

With the WEMOS D1R2&mini board selected, it works fine. See:

[Jason2866]

Try a lower upload speed

For many D1 mini (clones) this speed is impossible.
Try 115200

[JAndrassy]

Crystal frequency 40 MHz? set 26MHz

[JRAlvarez2017]

Crystal frequency 26MHz does not work either.
Guys, I am fine with version 2.4.2, is works very well, really reliable.
Just wanted to know if I was missing something with 2.5.2.
I think it would be nice and helpful for the users to write in the front page something saying "versions above 2.4.2 are β" or however you want to word it.
Thanks for your help.