why the num_classes=0?

[fsted]

hi,thanks for the code ,but when i try to train the MaskCLIP+, I found an error:
model= dict( type='EncoderDecoder', pretrained='open-mmlab://resnet101_v1c', backbone=dict( type='ResNetV1c', depth=101, num_stages=4, out_indices=(0, 1, 2, 3), dilations=(1, 1, 2, 4), strides=(1, 2, 1, 1), norm_cfg=dict(type='SyncBN', requires_grad=True), norm_eval=False, style='pytorch', contract_dilation=True), decode_head=dict( type='MaskClipPlusHead', in_channels=2048, channels=1024, num_classes=0, dropout_ratio=0, ...

why the num_classes of decode_head=0? It may cause an indexerror. how to solve it?
Looking forward to your reply😄