missing cumtapcnt field

[Ingrid Nieuwenhuis]

I'm (trying to) beamform, but I get the following error:

reference to non-existent field 'cumtapcnt' 
In prepare_freq_matrices line 124.
Ntrials = length(freq.cumtapcnt)

I used freqanalysis method 'mtmconvol' to do make the freq, and it indeed 
doesn't contain a 'cumtapcnt'

      cfg = [];
      cfg.method = 'mtmconvol';
      cfg.output = 'powandcsd';
      cfg.foi             = 90;
      cfg.t_ftimwin       = 0.5;
      cfg.tapsmofrq       = 30;
      cfg.pad             = 'maxperlen';
      cfg.taper           = 'dpss';
      cfg.keeptrials      = 'yes';
      cfg.keeptapers      = 'no';
      cfg.toi             = 0.75 
        
      freq_BF = freqanalysis(cfg, data);

So my questions: 
- Why doesn't my freq contain a cumtapcnt field. Should I have kept my 
tapers (cfg.keeptapers = 'yes')?
- Can I solve this without having to freqanalysis my data all over again, I 
can see in my freq.crsspctrm = [76 x 11476 double] that I have 76 trials. 
Can I for instance just make a vector of ones with length 76 and put that 
in my freq, or will that create problems?

Thanks a lot,
Ingrid