PNG file attached to proposal showing access error

[#1]

Hi, I submitted a proposal with 3 image files attached (1 JPG and 2 PNG files). The 2 PNG files are not being displayed, Upwork is showing an access error.
According to your documentation PNG files are supported for upload.
You can see the error message here:
https://www.screencast.com/t/fPdZ2xj1

Please fix.

Thanks
Gulam

[#2]

Hi Gulam,

Can you clear your cache and cookies or use another browser to send a proposal and check if the problem still continues.