Pytorch UnpicklingError: A load persistent id instruction was encountered
My dataloader raises this error when loading its files:
UnpicklingError                           Traceback (most recent call last)
&lt;ipython-input-14-cb081a68afbe&gt; in &lt;module&gt;
----&gt; 1 torch.load(&quot;/network/tmp1/ccai/data/labelbox_2020/imgs/AB_304.png&quot;)

~/.conda/envs/omnienv/lib/python3.8/site-packages/torch/serialization.py in load(f, map_location, pickle_module, **pickle_load_args)
    593                     return torch.jit.load(opened_file)
    594                 return _load(opened_zipfile, map_location, pickle_module, **pickle_load_args)
--&gt; 595         return _legacy_load(opened_file, map_location, pickle_module, **pickle_load_args)
    596 
    597 

~/.conda/envs/omnienv/lib/python3.8/site-packages/torch/serialization.py in _legacy_load(f, map_location, pickle_module, **pickle_load_args)
    762             &quot;functionality.&quot;)
    763 
--&gt; 764     magic_number = pickle_module.load(f, **pickle_load_args)
    765     if magic_number != MAGIC_NUMBER:
    766         raise RuntimeError(&quot;Invalid magic number; corrupt file?&quot;)

UnpicklingError: A load persistent id instruction was encountered,
but no persistent_load function was specified.


What's bugging me is that I'm not doing multiple loads from the same process as pointed out here.
Could it be that this error is triggered by multiple python processes reading the same file?
pytorch 1.7 on ubuntu 18 with python 3.8

I found it: this error can be triggered when using torch.load on the wrong type of data, a .png image in this case.
