@sim - it’s happened again, downloaded and installed the latest version, ran and played with it for a couple of days. No probs. Ran it today. Closed it confident that it would be OK and when I ran it just now (same day) back to the projected new version. Can’t explain it.
Edit: re-installed 3.17(611) version for the mo, don’t want to lose out on coding in Codea, thanks again @sim .