Unable to load a checkpoint for a previously trained Faster R-CNN detector

Dear all,

I was training a faster r-cnn for two weeks and, somehow, it crashed last night..

I was saving the checkpoints after each epoch but now, if I try to start a new training with the last one (or any other) I receive:

Error using vision.internal.cnn.rcnnDatasetStatistics>iGetRPNSoftmaxLayerSource (line 125)

Expected one output from a curly brace or dot indexing expression, but there were 0 results.

Error in vision.internal.cnn.rcnnDatasetStatistics (line 17)

params.RPNSoftmaxLayerSource = iGetRPNSoftmaxLayerSource(analysis);

Error in trainFasterRCNNObjectDetector>iCollectImageInfo (line 1674)

imageInfo = vision.internal.cnn.rcnnDatasetStatistics(trainingData, rpnLayerGraph, imageInfoParams);

Error in trainFasterRCNNObjectDetector (line 423)

[imageInfo,trainingData,options] = iCollectImageInfo(trainingData, rpn, iStageOneParams(params), params, options);

And the detector object seems to be empty:

fasterRCNNObjectDetector with properties:

ModelName: 'MCs'

Network: []

AnchorBoxes: [3×2 double]

ClassNames: {}

MinObjectSize: [16 16]

Can't I resume training with these chechpoints where it left off?

And, if not, what went wrong during the saving of these checkpoints?!

I don't know if it matters but I was training with the Training method "four-step".

Please, please, any help??