Hi, it seems I have found a workaround for uploading.
PHP7 didn't help after changing so I went back to 5.6.
But what I have found is that problem images are not the jpeg 150K packed size but the final opened image size, so even if a jpeg is 60k in file size if the opened image (if viewed in Photoshop) is approx over 4.2mb after expanding it won't upload to the server. So for example 1920x1080 images are larger than this and fail even if 150k filesize but a cropped 1920x720 uploads ok.
It's going to be important in the future to upload even higher quality images as 1920x1080 isn't that large anymore on high definition monitors
I guess I should have mentioned this before, but I thought it was the upload file size which was the issue :)
I didn't realise there was this restriction, is this still a server or indexhibit restriction? If this is still a server issue it makes sense. But I changed the max file sizes in indexhibit to allow higher resolutions and file sizes. if the server is not allowing me to open larger images I guess I need to change the server....