Release Notes
8.0.16.3480: Aug 20 2019
Windows - Plastic: improved the embedded semanticmerge to take into account the preferences related to the merge conflict resolution (manual or automatic when possible).
Windows - Plastic, Gluon: some users reported that, in Gluon, the purpose of the checkin comments textbox wasn't obvious. Our bad! Luckily, that's what hint texts are for - so now both Plastic and Gluon have a hint text so you never leave a checkin comment empty ever again!

All platforms - Fixed the checkin error 'There has been an unexpected error "The item should be found on the server tree. Child [readme.txt]. Parent [doc]". For more information check the server log.' trying to checkin a merge result on a workspace with cloaked items under some special circumstances.
Let's see a simplified case that reproduces the error that now is fixed:
1- Create a new workspace pointing to a new repository.
2- Add and checkin the following content:
/src
/src/foo.c
3- Cloak /src (the items remains loaded but as cloaked).
4- Create a child branch task from cset:0
5- Merge from main to task
6- Checkin the merge result -> The checkin failed with the following error: 'There has been an unexpected error "The item should be found on the server tree. Child [foo.c]. Parent [src]". For more information check the server log.'. Now it's fixed