opengl 4.3 compute shader not writing value to buffer - opengl

Question

I am having a weird problem with compute shaders since I changed the structure size of a buffer I was passing in to the shader.
struct Particle
{
vec3 position;
vec2 uv;
vec3 accumulated_normal;
int id;
int flattened_id;
int movable;
// can the particle move or not ? used to pin parts of the cloth
float mass;
// the mass of the particle (is always 1 in this example)
vec3 old_pos;
// the position of the particle in the previous time step, used as part of the verlet numerical integration scheme
vec3 acceleration;
// a vector representing the current acceleration of the particle
};
Defined like this. I was having problems trying to use the flattened id so I wanted to write the id's back to the buffer I was passing in. The shader looks something like this.
layout (local_size_x = 16, local_size_y = 1, local_size_z = 1) in;
void main()
{
unsigned int flattened_id = gl_LocalInvocationIndex;
particleBuffer.particles[0].id = 16;
particleBuffer.particles[1].id = 17;
particleBuffer.particles[2].id = 18;
particleBuffer.particles[3].id = 19;
//particleBuffer.particles[4].id = 20;
}
So till this point it is fine but the moment I uncomment the last line which is the particleBuffer.particles[4], the mesh vanishes from the screen. I have managed to change the position data from this mesh before but this seems strange. I verified that I have indeed 16 elements of the buffer which I am passing in so it should not go out of bounds either (i.e. cloth1.particles.size() = 16). Any ideas ??
The entire code is here..
https://github.com/ssarangi/OpenGL_Cloth/tree/master/cloth_4_3_compute
glUseProgram(computeShader);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, cloth1.vertex_vbo_storage);
glBufferData(GL_SHADER_STORAGE_BUFFER, cloth1.particles.size() * sizeof(Particle), &(cloth1.particles[0]), GL_DYNAMIC_COPY);
glDispatchCompute(1, 1, 1);
{
GLenum err = gl3wGetError();
}
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, 0);
glBindBuffer(GL_ARRAY_BUFFER, cloth1.vertex_vbo_storage);
Particle * ptr = reinterpret_cast<Particle *>(glMapBufferRange(GL_ARRAY_BUFFER, 0, cloth1.particles.size() * sizeof(Particle), GL_MAP_READ_BIT));
memcpy(&cloth1.particles[0], ptr, cloth1.particles.size()*sizeof(Particle));
glUnmapBuffer(GL_ARRAY_BUFFER);
glBindBuffer(GL_ARRAY_BUFFER, 0);
*********************** EDITED with Andon's comments ******************************
This is the new layout from the C++ side.
struct Particle
{
vec4 position;
vec2 uv;
vec4 accumulated_normal;
vec4 old_pos; // the position of the particle in the previous time step, used as part of the verlet numerical integration scheme
vec4 acceleration; // a vector representing the current acceleration of the particle
int id;
int flattened_id;
int movable; // can the particle move or not ? used to pin parts of the cloth
float mass; // the mass of the particle (is always 1 in this example)
The GLSL side definition. What I am unsure about is if the padding elements need to be included in the glsl structure or not. It still doesn't update the ID's.
struct Particle
{
vec4 position;
vec2 uv;
vec4 accumulated_normal;
vec4 old_pos; // the position of the particle in the previous time step, used as part of the verlet numerical integration scheme
vec4 acceleration; // a vector representing the current acceleration of the particle
int id;
int flattened_id;
int movable; // can the particle move or not ? used to pin parts of the cloth
float mass; // the mass of the particle (is always 1 in this example)
};