I got this error running a slightly modified version of one of your examples running it on an 8266. Hard to see how my small mods could have caused this. Here's more of the compiler ouput <D:\David\MyDocuments\Arduino\libraries\SoftTimers\src/SoftTimers.h: In constructor 'SoftTimerMillis::SoftTimerMillis()':

D:\David\MyDocuments\Arduino\libraries\SoftTimers\src/SoftTimers.h:122:40: error: invalid conversion from 'long unsigned int ()()' to 'SoftTimer::CounterFunctionPointer {aka unsigned int ()()}' [-fpermissive]

SoftTimerMillis() : SoftTimer(&millis)

                                    ^

D:\David\MyDocuments\Arduino\libraries\SoftTimers\src/SoftTimers.h:36:3: error: initializing argument 1 of 'SoftTimer::SoftTimer(SoftTimer::CounterFunctionPointer)' [-fpermissive]

SoftTimer(CounterFunctionPointer iCntFuncPtr);

^
D:\David\MyDocuments\Arduino\libraries\SoftTimers\src/SoftTimers.h: In constructor 'SoftTimerMicros::SoftTimerMicros()':

D:\David\MyDocuments\Arduino\libraries\SoftTimers\src/SoftTimers.h:131:40: error: invalid conversion from 'long unsigned int ()()' to 'SoftTimer::CounterFunctionPointer {aka unsigned int ()()}' [-fpermissive]

SoftTimerMicros() : SoftTimer(&micros)

D:\David\MyDocuments\Arduino\libraries\SoftTimers\src/SoftTimers.h:36:3: error: initializing argument 1 of 'SoftTimer::SoftTimer(SoftTimer::CounterFunctionPointer)' [-fpermissive]

SoftTimer(CounterFunctionPointer iCntFuncPtr);>

Here's the code
<#include <SoftTimers.h>
#include "Arduino_DebugUtils.h"

// My libraries
#include "boardconfig.h"

/**************************************************

• Wait 1 second, turn on a LED for 0.3 second.
  **************************************************/
  SoftTimer delayTimer; //millisecond timer
  SoftTimer ledTimer; //millisecond timer

void setup() {
pinMode(ledPin, OUTPUT);

Serial.begin(115200);

//update timers
delayTimer.setTimeOutTime(1000); // 1 second.
ledTimer.setTimeOutTime(2000); // 2 second.

//start counting now
delayTimer.reset();
ledTimer.reset();
}

void loop() {
if (!delayTimer.hasTimedOut())
{
Serial.println("waiting...");

//reset LED timer so that is does not time out before delayTimer
ledTimer.reset();

}

//did we waited long enough ?
else if (delayTimer.hasTimedOut() && !ledTimer.hasTimedOut())
{
Serial.println("turning LED ON...");

//turn ON the LED
digitalWrite(ledPin, HIGH);

}

//should the LED be turned OFF ?
else if (delayTimer.hasTimedOut() && ledTimer.hasTimedOut())
{
Serial.println("turning LED OFF...");

//turn OFF the LED
digitalWrite(ledPin, LOW);

//restart both timers
delayTimer.reset();
ledTimer.reset();

}
}>
and
</*

• Board config library
  */
  #ifndef BOARDCONFIG_H
  #define BD_VER 1 // set to board version being targetted
  #ifndef D5
  #if defined(ESP8266)
  #define D0 (16)
  #define D1 (5)
  #define D2 (4)
  #define D3 (0)
  #define D4 (2)
  #define D5 (14)
  #define D6 (12)
  #define D7 (13)
  #define D8 (15)
  #define TX (1)
  #define RX (3)
  #elif defined(ESP32)
  #define D5 (18)
  #define D6 (19)
  #define D7 (23)
  #define D8 (5)
  #define TX (1)
  #endif
  #endif

if BD_VER == 1

const int sclPin = D1;
const int sdaPin = D2;
const int fanPin = D3;
const int ledPin = D4;
const int piezoPin = D5;
const int thPin = D6;
const int h2oPin = D7;
const int adcPin = A0;

elif BD_VER == 2

const int sclPin = D1;
const int sdaPin = D2;
const int fanPin = D3;
const int ledPin = D4;
const int swrxPin = D5;
const int swtxPin = D6;
const int openPin = D7;
const int dirPin = D8;
const int adcPin = A0;

else

const int ledPin = D0;
const int sclPin = D1;
const int sdaPin = D2;
const int fanPin = D3;
const int fanspdPin = D4;
const int swrxPin = D5;
const int swtxPin = D6;
const int openPin = D7;
const int dirPin = D8;
const int adcPin = A0; //Connected to fault output of switch to fan
#endif //BD_VER logic
#endif BOARDCONFIG_H>