Start by going to Help → "Restart in Safe Mode" and see if it still happens with all plugins disabled.
If it does, we'll need more information — a Report ID, a link to a screenshot, whether this happens for all PDFs or just one, and any other details you can provide.
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If it does, we'll need more information — a Report ID, a link to a screenshot, whether this happens for all PDFs or just one, and any other details you can provide.