Thinking out-loud: issue must be in the function analysing the dragged object data. It could be that the data from a dragged image in firefox is base64 encoded ascii character, making it quite a big chunk of data for unity to analyze.
Thinking out-loud: issue must be in the function analysing the dragged object data. It could be that the data from a dragged image in firefox is base64 encoded ascii character, making it quite a big chunk of data for unity to analyze.