Error during Setup: importing ROI data

Dear experts,

When trying to run the Setup step in my connectivity analysis in Conn toolbox, an error occurs at "Step 5/7" while importing ROIs data. It reads as follows:

[color=#000080]ERROR DESCRIPTION:[/color]

[color=#000080]Error using spm_slice_vol[/color]
[color=#000080]File too small.[/color]
[color=#000080]Error in spm_read_vols (line 34)[/color]
[color=#000080]Y(:,:,p,i) = spm_slice_vol(V(i),spm_matrix([0 0 p]),V(i).dim(1:2),0);[/color]
[color=#000080]Error in conn_process (line 599)[/color]
[color=#000080]X0=spm_read_vols(V0);[/color]
[color=#000080]Error in conn_process (line 14)[/color]
[color=#000080]case 'setup', disp(['CONN: RUNNING SETUP STEP']); conn_process([0:4,4.5,5]);[/color]
[color=#000080]Error in conn (line 2999)[/color]
[color=#000080]else conn_process('setup');[/color]
[color=#000080]Error in conn_menumanager (line 119)[/color]
[color=#000080]feval(CONN_MM.MENU{n0}.callback{n1}{1},CONN_MM.MENU{n0}.callback{n1}{2:end});[/color]
[color=#000080]CONN v.16.b[/color]
[color=#000080]SPM12 + DEM FieldMap MEEGtools[/color]
[color=#000080]Matlab v.2012b[/color]
[color=#000080]storage: 248.0Gb available[/color]

It always occurs for the same subject (patient 18 out of 57), and when I remove this subject from the dataset the error now occurs for the next subject, so it doesn't seem to be dependent on the functional images. And I tried to run the analysis with 4D or 3D images, with the same result.

I also obtain the same error simply when clicking on the corresponding subject in the Setup window, in the "grey matter" or "white matter" section.

I am stuck and I hope someone can provide some useful advice!
Thank you in advance for your help

Eléna Chabran