hello
I was test press the photo upload button on my website when i was inspect my browser requests and see that you have some url that i can not see on my develop inspect tool.
This url i not have: photo-master/
I think you not use same photo plugin that i use or you have wrong "path" and folders installed on wrong place.
I will double check if i can find this photo-master/ path on my site. but i could not see such request in my developer tool
maybe that why you server respond with not find code
i have a suggestion for you:
try this demo website https://demo.oxwall.com/ and then upload a photo and inspect in crome and see if you got same URL request photo-master/ when press upload photo
and im 100% sure they who can read code can understand deeper what the issue is and i think this can bee solved because now we have find the errors and that is "first step" debug something
(the software is looking for something that not excisiting on your server.)
I think maybe you use a third part photo plugin or addon. try disable any third part plugin that use photos and albums
what is you FULLY path to your photo plugin? and your url path to your album photo files?