Hi Stardust1611,
Do you use the image in the resource as the Image of ToolStrip button? If you did so and delete the image from the resource in the VS designer, it cannot locate them and popup error at design time. Also it will raise error when compiled. If you delete these image file in Windows Explorer, you won't lose these image on ToolStripButton.
Do you bind your code to a source control? If so, you need to roll back to a previous version(before you delete resource) to get them back.
Sincerely,
Kira Qian
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