# Troubleshooting¶

Most things in Salvus are statically linked, except MPI, thus dynamic MPI libraries must be available. If these are not present, errors like the following happen:

error while loading shared libraries: libmpicxx.so.12: cannot
open shared object file: No such file or directory


On sites without central job submission system (thus usually single nodes), just let the Mondaic downloader also download MPI. It will but the MPI libraries in the lib/ folder and SalvusFlow will set the LD_LIBRARY_PATH accordingly when running Salvus.

For other sites, please load a suitable MPI module (see here for more details). In some cases the module system might not set the $LD_LIBRARY_PATH - then it has to be done manually in the SalvusFlow config file for the corresponding site. ### Jupyter kernel dies¶ If you see the Jupyter notebook kernel dying when importing parts of Salvus make sure that you have a valid license and an active internet connection. If one of these is the issue, there should be an error message in the terminal that started Jupyter notebook. For technical reasons we cannot show this message in the Jupyter notebook. ### Certificate errors while running the downloader¶ On old systems (or just having an old version of curl which might for example also happen when inside a conda environment) the certificate might not be valid, so errors like this one might occur when attempting to run Mondaic's downloader: curl: (77) error setting certificate verify locations: CAfile: /etc/pki/tls/certs/ca-bundle.crt CApath: none  In these cases you could attempt to fix your curl installation or just manually do what the get.mondaic.com script is doing: 1. Download either https://get.mondaic.com/salvus_downloader_linux or https://get.mondaic.com/salvus_downloader_osx (depending on your operating system) by whatever means possible (wget, browser, copy on other machine and scp it over, ...). 2. Give it execution rights and run it: shell$ chmod u+x salvus_downloader_* \$ ./salvus_downloader_*

3. The rest is business as usual.

### Illegal instructions¶

An error like

Illegal instruction


occurs if attempting to run a binary that has instructions that the current CPU cannot interpret. If you see this when running Salvus you likely downloaded the wrong binary for your system. Please see our documentation about instruction sets for more details.

### Error during import of salvus_flow¶

There was a recent update of the arrow package, which is used by SalvusFlow. For arrow versions prior to 0.14.4 you might receive the following error:

AttributeError: module 'arrow.factory' has no attribute 'ArrowParseWarning'


To check which version you have installed, run the following line in a terminal

python -c "import arrow; print(arrow.__version__)"


pip install --upgrade arrow