This option checks the integrity of the engine files. The launcher compares your installation with Epic’s official version and automatically re-downloads any files that are corrupted, incomplete, or damaged.
If the issue still happens after this, try creating a new empty project and see if it also freezes.
If it also happens in a new project, the problem is likely external to the project, such as your GPU drivers. In that case, it may help to roll back to a previous, more stable driver version, especially if the issue started after updating your drivers.
If it does not happen in a new project, then the issue is probably related to a specific asset, shader, or corrupted cache in the original project.