Well, do not worry, you can download Sony action cam video recovery software to recover deleted videos from Sony 4K Action Cam. See this tutorial
Sony Action Cam data recovery
The data recovery software is easy to use. You can recover deleted photos and videos from Sony actions cameras, such as Sony FDR-X1000V, FDR-X3000, HDR-AS300, HDR-AS50, HDR-AS300R, FDR-X3000R.
You can follow this step by step tutorial
Step 1. Take out memory card from your Sony Action Cam.
Step 2. Connect memory card to computer with a card reader
Step 3. In data recovery software, select memory card, and then choose Next to scan for lost files.
Step 4. After scanning completed, you can see list of recoverable files in result page. Select files you want to recover, and then press Recover to save them.
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