The PDF file is not displayed correctly.
When I open the PDF document (A scientific literature: Cell recruiting chemokine-loaded sprayable gelatin hydrogel dressings for diabetic wound healing), a black fan will appear in the upper left corner of the picture in the document.
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layers.acceleration.disabledtotrue, and then restart Zotero. It should fix the issue, but can affect performance.If it doesn't help revert the setting back.