Plan and test game mechanics

A mechanic needs an observable rule: an action, a change in state and feedback to the player. Before adding more systems, test whether the first action, win condition and restart work together. The existing guides below provide the starting workflow and debugging checks.

Open Mechanics collection ↗

Prepare a game for publishing

Publishing starts with a game that can be tested, understood and maintained. Check the available creator controls, audience settings and safety requirements before a release. Use the publishing guide for the sequence, and the troubleshooting guide for an actual blocked step.

Open Publish collection ↗

BC-0149 · TROUBLESHOOTING

Editorial review 2026-09-26

Roblox Build Project Will Not Open

If a Build project is visible but will not open, keep its identity and record the result of selecting that specific project. Determine whether the failure is isolated to that entry or affects the creation surface more broadly, using existing projects only when a safe comparison is available.

Symptom

An identifiable creation entry is present, but selecting it does not open a usable project.

Immediate action

Preserve the project identity and exact opening result without editing or recreating it.

Diagnostic branches

The selected target is uncertain because entries have similar names.: Verify the intended project identity before retrying the opening action.
A specific requirement or error is shown.: Follow that notice's legitimate path and retain its exact wording.
A safe comparison with another existing project is possible.: Record whether the boundary appears project-specific without inferring a technical cause.
No safe existing comparison is available.: Keep the single-project report and seek official assistance rather than creating a new test game.
The failure follows a known editing handoff.: Add the version/action history and use handoff-specific guidance without making another edit.

Least-destructive change

Inspect existing entry and error information, with an optional safe existing-project comparison only.

Retest

Inventory presence and opening success remain separate states.
The report identifies the same project across attempts.
A project-specific failure is not automatically labelled corruption or deletion.

Escalation

Give official support the project identity, opening trace and any known editing history when the notice does not supply a usable resolution. Do not upload private source or account credentials to a public troubleshooting thread.

Working notes

Record the selected entry, not just its title. Similar names can hide a target mistake. Include the action taken, any acknowledgement and the exact notice, blank state or loading behavior reached. The visible entry is evidence of inventory presence even if opening fails.

A comparison with another existing project can narrow the boundary, but it is optional. Use only a project you are authorized to open and only where leaving the current state will not discard work. Do not generate a new game or purchase usage merely to create a comparison case.

Keep version and editing history available when relevant. If the failure followed a Studio handoff or another known change, record the action without performing another edit to test it. The project history can guide the next question, but timing alone does not establish causation.

Do not infer corruption, deletion or a permissions change from a generic opening failure. A specific message may establish a relevant requirement; an unexplained failure should remain unexplained in the report. Preserve the original project rather than overwriting it with a reconstruction.

Examples

Opening trace: intended project entry visible → selected → progress indication → exact error shown. Keep the entry identity and error together rather than reporting a missing creation.
Optional comparison: another already-existing project opens in the same account and surface. Record a project-specific difference, not a diagnosed corrupt file.
No comparison available: this is the only known creation. Report the single-project observation honestly without creating another paid request to test the app.