Upload Reference Data in Custom Job Dialog

Hey all,
I have a problem in v1.8.3. I have setup a site and defined “insitu” data via the Site Tab Web GUI. The in-situ zipped shapefile was uploaded successfully (and can then be found in the /archive/insitu folder).

If I start a L4A job via the dashbord GUI, the prcoessing starts.

If I would like to start a L4A job via the custom jobs section, I get an error trying to upload the same insitu/referende zip-file than above. The error states "Missing shape file due to an error with your selected file (Unable to access your selected file).

Can I remove the in-situ site data from the Sites definion tab? Where is this information stored in the DB?

Regards
oliver

PS: I already tried

sudo chmod 777 /mnt/upload

There is an error on 1.8.3. This patched solved the upload for me