ROI-to-ROI menu error.

Dear Conn Toolbox community, 

thank you for your being so consistently helpful. I am trying to perform an ROI-to-ROI analysis in the Conn interface. Whenever I so much as try to open the ROI-to-ROI menu, however, it immediately throws an error: 

ERROR DESCRIPTION:

Matrix dimensions must agree.
Error in conn_process (line 4685)
nsubjects=find(any(X(:,nsubjecteffects)~=0,2)&~any(isnan(X(:,nsubjecteffects)),2)&~any(any(all(isnan(y),2),3),4));
Error in conn_process (line 57)
case 'results_roi', [varargout{1:nargout}]=conn_process(17,varargin{:});
Error in conn (line 9255)
CONN_h.menus.m_results.roiresults=conn_process('results_ROI',CONN_x.Results.xX.nsources,CONN_x.Results.xX.csources);
Error in conn_menumanager (line 134)
feval(CONN_MM.MENU{n0}.callback2{n1}{1},CONN_MM.MENU{n0}.callback2{n1}{2:end});
CONN18.b
SPM12 + DAiSS DEM FieldMap MEEGtools
Matlab v.2018b
project: CONN18.b

Due to the variable names in the error lines I assumed it might have had something to do with there somehow being a mismatch in number of files in my functional and structural setup, but I determined that not to be true. It will also throw this error whenever I try 'results explorer' or 'graph theory' from that same menu. Would there happen to be someone who can tell me what could be causing this issue? 

Kind regards, 
Romke Hannema