Reading old .ce file fails

Hi, when I try to read old .ce files with the new 2.1 ICET version it fails with the following error:

Input In [6], in <cell line: 1>()
----> 1 ce = ClusterExpansion.read("test.ce")

File ~/.local/lib/python3.8/site-packages/icet/core/cluster_expansion.py:346, in ClusterExpansion.read(filename)
    344 cs_file.write(tar_file.extractfile('cluster_space').read())
    345 cs_file.close()
--> 346 cs = ClusterSpace.read(cs_file.name)
    347 items = pickle.load(tar_file.extractfile('items'))
    348 os.remove(cs_file.name)

File ~/.local/lib/python3.8/site-packages/icet/core/cluster_space.py:757, in ClusterSpace.read(filename)
    755     else:  # for backwards compatibility
    756         for value in items['pruning_history']:
--> 757             cs._pruning_history(value)
    759 return cs

TypeError: 'list' object is not callable

The problem is not related to the metadata as in Issue #572 (closed), it is a problem with loading the old ClusterSpace object. I still have a ICET 1.4 installation which can read the old .ce file, so I also tried saving the CE parameters separately and combining it with a ClusterSpace object. Reading/Writing the old ClusterSpace object fails with the same error and unfortunately the old CE has been pruned, therefore the number of clusters in a newly created ClusterSpace object do not fit to the number of parameters. Is there any other workaround to get the old CE working with ICET 2.1?