DLL Load Failed while importing _arpack error

I have recently gone from Python 3.10 back to Python 3.9 in order to use Cartopy.

My Py3.10 installation was a pip installation, and has been fully uninstalled.

My Py3.9 installation is using Anaconda3.

My python programs used to run without problems on 3.10, and they still do run well on my laptop with Py3.9 Anaconda installation, but they will no longer run on my desktop since rolling back to Py3.9.

Here is the console output I get:

The line “from obspy.signal import filter” appears to be the line in my program that results in the problem when obspy calls scipy.

Any suggestions on how to fix this? I have uninstalled and reinstalled anaconda a couple of times and updated packages as much as anaconda will allow. Seems all OK on my laptop but will not run on my desktop.



I don’t think this has anything to with obspy. Looks like a broken scipy installation. If there is nothing special in your anaconda setup that would be painful to set up again from scratch, I think easiest would be to just get rid of anaconda and install fresh. Less invasive would be to uninstall obspy and scipy and install it again, maybe.

It seems you are working in the base environment, btw? I would encourage leaving the base environment alone and work in a dedicated obspy environment, that way when you want a fresh start you can simply remove that environment and make a new one without having to install the whole anaconda thing again.

Hope it helps, let us know if you need more help.

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Thanks for your help Tobias! I’ve got it working again.

For the record, I found an entry in the PYTHONPATH environment variable that I missed when Uninstalling a previous version of PY3.10. That by itself didn’t fix the problem, but may have affected the Scipy install.

So I uninstalled Obspy, Cartopy and Scipy and then reinstalled Scipy in the base environment.

I then created a new environment for Obspy and Cartopy and it’s all working now.

Thanks again!


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