Guessing what exactly does it:
probably related to a used plugin (not core) check if there is (pluginmanager) (NOT the update button itself now) an extra icon (right side) that seems to either update or needs extra install (instead of 2 icons 3 are shown). Execute from there.
Then try to apply the main update button.
If this does not show results use https://github.com/e107inc/e107
(right bottom zip pack), unpack and delete install php and overwrite the present files. The betapack from org is a little dated and much more updates and issues where worked out in the zip pack.
As always !! BACKUP first.