Ok i have spent hours on this. i don't think the problem is with elfinder.
PDF files work fine whether or not it is enabled.
As soon as you upload a graphic file gallery setting bombs out as per the jpg previously loaded here.
As soon as the graphic file is deleted you can access settings again.
I have tried several files and several formats to check for corruption but the same problem
Am i missing a setting or something that is new with 26.x?
Has anyone else who reads this done a clean install and had this problem or done an upgrade and had this problem for that matter ?
Or has anyone done a clean install of V 26.0 and not had any problems with file gallery settings? for that matter
Just for the hell of it i renamed a pdf file to jpg.... that did not cause any problems with gallery settings ... the file was useless though of course.
Renaming a jpg as a pdf did still cause problems.
I suspect that anyone who does an upgrade will have this problem too.