Error processing HERMES data

Hi all,
While analyzing HERMES data using Osprey (version 2.4.0), we got the following error:

 Elapsed time 0.135881 seconds
Data type Philips SDAT is already coil-combined.
Timestamp September 05, 2023 13:36:09 Osprey 2.4.0  OspreyProcess
Processing data from dataset   1 out of   1 total datasets...
Error using chol
Matrix must be positive definite.

Error in op_robustSpecReg>whittaker (line 579)
C = chol(W + lambda*(D'*D));

Error in op_robustSpecReg>BaselineModeling (line 498)
z_real = whittaker(z_real, 2, 1e3);

Error in op_robustSpecReg>SignalFilter (line 401)
[z.real, z.imag] = BaselineModeling(spec, r_flag, q_flag, in);

Error in op_robustSpecReg (line 140)
                DataToAlign(:,jj) = SignalFilter(spec(:,jj), lipid_flag, water_flag, in);

Error in OspreyProcess (line 224)
                            [raw, fs, phs, weights, driftPre, driftPost]     = op_robustSpecReg(raw, seq, 0,refShift_ind_ini); % Align and average

Error in OspreyCommands_singleHERMES_MRI (line 8)
MRSCont = OspreyProcess(MRSCont); % Process data

Until recently we used the same scripts without problems, so we believe something might have gone wrong during our last data acquisition.
Do you know what the problem might be and how to fix it?

Thank you in advance!