Hadd output missing histograms from input files

I’ve searched for an existing topic on this, and have found some very similar cases that seem to have been fixed, but I’m still seeing this issue.

I’m running ‘hadd’ over many files, 955 input files. Each file contains histograms in a directory structure that is common. Also, each file contains only histograms that are not existing in any other files so there is really no adding going on, only merging of the directory structure and putting all the histograms into the same file.

I’m using ROOTSYS:

What I find is that even though the input file is listed in the ‘hadd’ file list that is printed at the start of running it, such as:
"hadd Source file #: "

and it seems to be listed when looping over the directory structure, such as:
“hadd Target path: <filename:directory path inside file>”

however when I open the output file and navigate to the directory it doesn’t exist. All histograms from an entire file are missing when this problem occurs and only a small number of files are missing O(10).

I’m running on AFS so if you need a test case, I can give you access to my AFS area to run over.