Missing or incorrect image error when printing invoice

If you receive an error similar to: FPDF error: Missing or incorrect image file: uploads/graphic_big1.jpg, please make sure Apache has write access to the nolapro/uploads folder.

Similarly, if you receive this error for B2B invoices, make sure Apache has write access to the nolapro/b2b/uploads folder.

This error shouldn't occur for those with the standard Windows installation, rather this is more likely with the Linux version.

Other possible causes of this or a similar error may be that the uploaded file isn't a .png or .jpg type, or that the .png file has not been flattened into a single layer.