error in using fscanf

I have a script like this:

%Inputing POE

file_01='POE_0.01.txt';

fid=fopen(file_01, 'r');

FileName_01=fscanf(fid,'%g %g %g', [3,Inf])';

Mag_01=FileName_01(:,1); % moment magnitude

Dist_01=FileName_01(:,2); % distance

POE_01=FileName_01(:,3); % probability of exceedance

I = (mod(1:length(Mag_01),30)==1);

Mag = Mag_01(I);

Dist = Dist_01(1:30);

POE_01 = reshape(POE_01,30,15);

marginal(1:15,1) = sum(POE_01);

file_POE = ['POE_0.5.txt','POE_0.2.txt','POE_0.1.txt','POE_0.05.txt', ...

'POE_0.02.txt','POE_0.01.txt','POE_0.005.txt'];

for i = 1:7

file_temp=file_POE(i);

fid=fopen(file_temp, 'r');

FileName_temp=fscanf(fid,'%2.2f %g %g', [3,Inf])';

POE=FileName_temp(:,3); % probability of exceedance

marginal(1:15,i)=sum(reshape(POE,30,15));

temp=sum(marginal);

hold on

plot(Mag,marginal(1:15,i)/temp(i),'DisplayName',file_POE(i))

xlabel('Magnitude (Mw)');

ylabel('Contribution to the Hazard');

end

xlim([4.5 8.8])

legend

I got a massage about :

Error using fscanf

Invalid file identifier. Use fopen to generate a valid file identifier.

Error in inputing_data (line 73)

FileName_temp=fscanf(fid,'%g %g %g', [3,Inf

Is there any one can help?