Cant insert banner/background image

Tryng to style a contact form but i′m unable to insert a background image – the dialog box runs correctly, uploads the images correctly, but upon pressing “insert” i just get a blank dialoue box with no further messages and the image doesn′t show in the form styler when i am forced to x it out of the said box – what do i do wrong? The bgimage is 15 kb jpg so it should be within the size limitations, and I have also tried different image sizes to see if this may be the error but no luck… otherwise thanks for an absolutely fantastic plugin!

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