I would need to see the actual error, which should mention where the incompatibility is. However, please note that this can happen because Pandas, by default, infers data types from data.
For such cases where you may have mixed data in the same column, the fix is to use "infer_with_pandas=False" with the get_dataframe() method like below:
dataset = dataiku.Dataset("dataset_name")
df = dataset.get_dataframe(infer_with_pandas=False)
If this does not help, please provide the full error message/stack trace.