Issue with Iron Python

Yesterday, I tried to run a script that was working a week ago and it crashed. After having disabled part of it I was able to find the problem: it seems to be related with my Python script node. Here is the error:

Warning: IronPythonEvaluator.EvaluateIronPythonScript operation failed.
Could not load file or assembly ‘IronPython, Version=2.7.0.40, Culture=neutral, PublicKeyToken=7f709c5b713576e1’ or one of its dependencies. Le fichier spécifié est introuvable (specified file not found).

I am using Dynamo 0.8.3.2256 and Iron Python 2.7.5 is installed on my computer.

I wanted to update my dynamo version to a more recent one in order to check if it could help however, I am using some stockroom nodes and was not able to install them from the .exe on a newer version (node not loaded by Dynamo).

Do you have any idea how to solve this issue?