user48315: Okay so this is the code for my receiver. 
This is quite confusing so let's dub Receiver = DEVICE 1 and Transmitter = DEVICE 2
DEVICE 1: NRF24L01+, HC-05 (Bluetooth)
DEVICE 2: NRF24L01+
So DEVICE 1 will receive data from DEVICE 2. Also When it receives data from my phone that is connected to the HC-05 module, it will radio.StopListening and radio.write.
But for some reason, after i do radio.StopListening, radio.write doesnt work.
Currently, DEVICE 2 has a very simple code to receive data being sent from DEVICE 1. I've done this just to check if there's any data being sent when DEVICE 1's HC-05 module receives data.
Code:

#include "Arduino.h"
#include <nRF24L01.h>
#include <printf.h>
#include <RF24.h>
#include <RF24_config.h>

RF24 radio(9, 8);

byte addresses[][6] = {"1Node","2Node"};

void setup() {
  Serial.begin(9600);
  radio.begin();
  radio.setPALevel(RF24_PA_MIN);
  radio.setDataRate(RF24_2MBPS);
  radio.setChannel(124);

  // Open a writing and reading pipe on each radio, with opposite addresses
  radio.openWritingPipe(addresses[0]);
  radio.openReadingPipe(1, addresses[1]);
}

void loop() {
  unsigned char rf_data; //Make a variable to store the data
  unsigned char bt_data;
  unsigned char tosend;
  radio.startListening();

  if (radio.available()){
    while (radio.available()){
      radio.read(&rf_data, sizeof(rf_data));
      Serial.println(rf_data);
      }
    }

  if (Serial.available()>0){
    while (Serial.available()>0){
      bt_data = Serial.read();
      radio.stopListening();
      Serial.println(bt_data); //----------- I'M ABLE TO SERIAL PRINTLN ----
      radio.write(&bt_data, sizeof(bt_data)); //-------- BUT I'M UNABLE TO PERFORM THIS CODE HERE FOR SOME REASON
      }
    }

}

I've added comments to show which part works and which part doesn't
I hope this question isn't too hard to understand.

user40986: There could be few reasons but, firstly I would like to ask you to check if your write command is working at all. Try to disable reading mode and leave just write mode:
#include "Arduino.h"
#include <nRF24L01.h>
#include <printf.h>
#include <RF24.h>
#include <RF24_config.h>

RF24 radio(9, 8);

byte addresses[][6] = {"1Node","2Node"};

void setup() {
  Serial.begin(9600);
  radio.begin();
  radio.setPALevel(RF24_PA_MIN);
  radio.setDataRate(RF24_2MBPS);
  radio.setChannel(124);

  // Open a writing and reading pipe on each radio, with opposite addresses
  radio.openWritingPipe(addresses[0]);
  //radio.openReadingPipe(1, addresses[1]);
}

void loop() {
  unsigned char rf_data; //Make a variable to store the data
  unsigned char bt_data;
  unsigned char tosend;
  //radio.startListening();

 // if (radio.available()){
 //   while (radio.available()){
 //     radio.read(&rf_data, sizeof(rf_data));
 //     Serial.println(rf_data);
 //    }
 //   }

  if (Serial.available()>0){
    while (Serial.available()>0){
      bt_data = Serial.read();
      //radio.stopListening();
      Serial.println(bt_data); //----------- I'M ABLE TO SERIAL PRINTLN ----
      radio.write(&bt_data, sizeof(bt_data)); //-------- BUT I'M UNABLE TO PERFORM THIS CODE HERE FOR SOME REASON
      }
    }

}

Try above code and if it will not work change RF24_2MBPS to RF24_1MBPS and RF24_PA_MIN to RF24_PA_LOW on both modules (transmitter and receiver)

48315: <p>Okay so this is the code for my receiver. </p>

<p>This is quite confusing so let's dub Receiver = <code>DEVICE 1</code> and Transmitter = <code>DEVICE 2</code></p>

<p><code>DEVICE 1</code>: NRF24L01+, HC-05 (Bluetooth)</p>

<p><code>DEVICE 2</code>: NRF24L01+</p>

<p>So <code>DEVICE 1</code> will receive data from <code>DEVICE 2</code>. Also When it receives data from my phone that is connected to the HC-05 module, it will <code>radio.StopListening</code> and <code>radio.write</code>.</p>

<p>But for some reason, after i do <code>radio.StopListening</code>, <code>radio.write</code> doesnt work.</p>

<p>Currently, <code>DEVICE 2</code> has a very simple code to receive data being sent from <code>DEVICE 1</code>. I've done this just to check if there's any data being sent when <code>DEVICE 1</code>'s HC-05 module receives data.</p>

<p>Code:
</p>

<pre class="lang-cpp prettyprint-override"><code>#include "Arduino.h"
#include &lt;nRF24L01.h&gt;
#include &lt;printf.h&gt;
#include &lt;RF24.h&gt;
#include &lt;RF24_config.h&gt;

RF24 radio(9, 8);

byte addresses[][6] = {"1Node","2Node"};

void setup() {
  Serial.begin(9600);
  radio.begin();
  radio.setPALevel(RF24_PA_MIN);
  radio.setDataRate(RF24_2MBPS);
  radio.setChannel(124);

  // Open a writing and reading pipe on each radio, with opposite addresses
  radio.openWritingPipe(addresses[0]);
  radio.openReadingPipe(1, addresses[1]);
}

void loop() {
  unsigned char rf_data; //Make a variable to store the data
  unsigned char bt_data;
  unsigned char tosend;
  radio.startListening();

  if (radio.available()){
    while (radio.available()){
      radio.read(&amp;rf_data, sizeof(rf_data));
      Serial.println(rf_data);
      }
    }

  if (Serial.available()&gt;0){
    while (Serial.available()&gt;0){
      bt_data = Serial.read();
      radio.stopListening();
      Serial.println(bt_data); //----------- I'M ABLE TO SERIAL PRINTLN ----
      radio.write(&amp;bt_data, sizeof(bt_data)); //-------- BUT I'M UNABLE TO PERFORM THIS CODE HERE FOR SOME REASON
      }
    }

}
</code></pre>

<p>I've added comments to show which part works and which part doesn't</p>

<p>I hope this question isn't too hard to understand.</p>
 40986: <p>There could be few reasons but, firstly I would like to ask you to check if your write command is working at all. Try to disable reading mode and leave just write mode:</p>

<pre><code>#include "Arduino.h"
#include &lt;nRF24L01.h&gt;
#include &lt;printf.h&gt;
#include &lt;RF24.h&gt;
#include &lt;RF24_config.h&gt;

RF24 radio(9, 8);

byte addresses[][6] = {"1Node","2Node"};

void setup() {
  Serial.begin(9600);
  radio.begin();
  radio.setPALevel(RF24_PA_MIN);
  radio.setDataRate(RF24_2MBPS);
  radio.setChannel(124);

  // Open a writing and reading pipe on each radio, with opposite addresses
  radio.openWritingPipe(addresses[0]);
  //radio.openReadingPipe(1, addresses[1]);
}

void loop() {
  unsigned char rf_data; //Make a variable to store the data
  unsigned char bt_data;
  unsigned char tosend;
  //radio.startListening();

 // if (radio.available()){
 //   while (radio.available()){
 //     radio.read(&amp;rf_data, sizeof(rf_data));
 //     Serial.println(rf_data);
 //    }
 //   }

  if (Serial.available()&gt;0){
    while (Serial.available()&gt;0){
      bt_data = Serial.read();
      //radio.stopListening();
      Serial.println(bt_data); //----------- I'M ABLE TO SERIAL PRINTLN ----
      radio.write(&amp;bt_data, sizeof(bt_data)); //-------- BUT I'M UNABLE TO PERFORM THIS CODE HERE FOR SOME REASON
      }
    }

}
</code></pre>

<p>Try above code and if it will not work change <code>RF24_2MBPS</code> to <code>RF24_1MBPS</code> and <code>RF24_PA_MIN</code> to <code>RF24_PA_LOW</code> on both modules (transmitter and receiver)</p>
