WifiManager to my project ERROR

I've added the WifiManager library to my project and I started getting this error

exit status 1
Error compiling for board NodeMCU 1.0 (ESP-12E Module).

I wanted to avoid using the hard-coding for the wifi which works wonderful to me, but I want to test my project on different wifis which would suck to have to reprogram the chip everytime but I started getting this long error. What is causing this problem to arise?

Ps. I use the 1.6.9 version of the arduino (because I'm using NodeMCU V3 which sadly uses this version only, from what I heard and actually saw) and I have installed the WifiManager library already.

The actual error is in the txt file attached to the topic.
Edit: I accidently uploaded the error file 2 times

WifiManager_error.txt (67.8 KB)

WifiManager_error.txt (67.8 KB)

I suggest you update your ESP core to version 2.4.0 (you appear to be using 2.1.0)