Common run errors and fixes

When Code Lab does not run the way you expect, the best fix is usually to simplify the problem instead of clicking Run repeatedly.

Common first-run problems

The workspace is still loading

If Python or the workspace runtime is still loading, wait a little longer before running again.

If Run looks unavailable while Python is preparing, that is usually readiness behavior, not a crash.

The workspace looks empty or incomplete

Check whether:

• the blocks you expected are really present
• a template finished loading
• the right widgets are active for what you are testing

Run starts but nothing useful appears

If the program starts but the output feels blank:

• confirm the relevant widget is active
• check whether the template you loaded depends on a widget such as display, timer, or table
• look for status changes like Pause or Stop to confirm the run actually started
• check the Log Timeline
• open the Generated Code panel and confirm the blocks produced something sensible

A template replaced work you meant to keep

If your old workspace disappeared:

• remember that loading a template replaces the current workspace
• import an earlier export if you saved one
• avoid loading another template until you know whether recovery is still possible

A practical recovery sequence

1. Stop the run if it is still active.
2. Reduce the workspace to the smallest example you can reason about.
3. Recheck the language selection.
4. Confirm the required widget is present.
5. Check where the output is supposed to appear.
6. Run again.

When to reload a template

Reload the template if:

• you changed too much and no longer know what broke
• the workspace no longer matches the tutorial or example you were following

When to import an earlier export

Import an older workspace if:

• the current one is badly broken
• you previously exported a stable version

That is often faster than debugging a heavily changed beginner project.