How to Fix Blocked SketchUp Extension (3 Steps)

This blocked SketchUp extension error is common when you install a new plugin. The extension is blocked because in the settings you have not allowed unconfirmed plugins to work. SketchUp has three loading-policy modes: Identified Extensions Only (loads only extensions digitally signed through the Extension Warehouse), Approve Unidentified Extensions, and Unrestricted (the default — loads everything). The block usually appears for one of two reasons: either your policy was set to “Identified Extensions Only” (common on IT-managed machines), or the plugin’s digital signature failed to validate even under the default Unrestricted mode — for example a re-zipped or edited .rbz. The ways to unlock a Blocked SketchUp plugin are very simple as follows:

• Step 1: Window ->Extension Manager
• Step 2: Extension Setting
• Step 3: Approve Unidentified Extensions

How to Fix Blocked SketchUp Extension: Step 1 — Open Extension Manager

Step 2: Extension Setting

By clicking on the gear icon on the upper right.

Step 3: Approve Unidentified Extensions

Press Confirm

Result

All blocked plugins have been opened.

Good to know

A few things that trip people up even after they change this setting:

• “Approve Unidentified Extensions” is not a one-time toggle — it shows a checklist of every unsigned extension at each launch, and you must tick the ones you want loaded that session. If you would rather not see that prompt every time, switch to “Unrestricted” instead, but only do so when you trust everything installed (it loads any plugin with no checks).
• Changing the loading policy to fix the blocked extension does not load the plugin immediately — you have to fully restart SketchUp because extensions are only evaluated against the policy at startup.
• “Unsigned” is not the same as “broken.” Signing only proves a file came from the Extension Warehouse unchanged; plenty of legitimate plugins distributed as a direct .rbz are simply unsigned, which is why this prompt exists.
• A plugin can still report “Blocked” even after you approve it if the package failed its signature check rather than being merely unidentified — for that case, remove it and reinstall a fresh download instead of toggling the policy, since a corrupted or partially extracted .rbz will never validate — reinstall the SketchUp extension from a fresh download.

Nguyen Huu Khanh

Architect turned developer