Deleting and reinstalling Zorro fixed the problem. However, when I installed more historical data (required for workshop 5) it crashed again with error 111. I removed the historical data and tried other historical data files until I found a combination that worked. Data files were downloaded here https://zorro-project.com/download.php and installed in the History/ directory.

Error 111 is not very descriptive. Apparently it can be triggered by incompatible data files. I understand everything in Zorro is optimized for speed so run-time checking is not preferred and a Segmentation Fault is thrown instead. However, perhaps Zorro can verify the data file once when it detects that a new one has been installed?

Anyway, I can now continue with the workshops. Thank you for your help