TCPDF html with image not working

I'm working on creating pdf with TCPDF library, i'm having issue creating pdf from html with image.

Pdf creation is worked beautifully in my localhost and staging server but when i moved it to live enviornment it fails to load and throwing error.

ErrorException in tcpdf.php line 7124:Illegal string offset 'masked'

I've applied googled answers but none worked for me.

When i'm removing the image from html, pdf is generating. But when i'm adding image, its throwing the above error.

I've checked the image url and its fine. Its been one whole day with no results.

It would be very helpful if someone can lead me to right way.

via Chebli Mohamed