Creating a data store for CNN Training

I am having a 4D array xy_RGBO(row,col,channel,sample)

This array has 1x11 values for each channel and four such channels are arranged in the 3rd dimension. This 3D block represents one image. The fourth dimension indicateds the index for each image. How can I create a data store to train CNN?

When I stored each image as TIFF file and the data store was created using

imds=imageDatastore(fullfile(rootFolder),'FileExtensions', '.tiff','IncludeSubfolders',true,'LabelSource','foldernames')

The following error appeared

Error in LeafDAGMultinput (line 160)

kkt_net = trainNetwork(imdsTrain,layers,opts); %data, layers, global training options

Caused by:

Layer 'input_stream_1': Missing input. Each layer input must be connected to the output of another layer.

Detected missing inputs:

input 'in2'

input 'in3'

Layer 'FCs_Connected': Missing input. Each layer input must be connected to the output of another layer.

Detected missing inputs:

input 'in2'