Failed to install app: Processing of multipart/form-data request failed. /home/dhis/tomcat-dhis/work/Catalina/localhost/ROOT/upload_bdb8f169_44a3_49ed_ae9a_76a80be552b3_00000000.tmp
Can you install other apps in your instance? Can you also check sharing settings in the system for that folder if Tomcat user does have write access to it.
By looking at the error message seems like you got installed dhis2 in *.unix environment.
Have a look at this article and see if you followed along. You should have dhis2 user in your instance and that particular user should have access to the folders, read/write:
About how to set permissions for folders in *.unix environments, follow this:
Just a note: As Clement noted above, the Bulk Load app is indicated as having a maximum DHIS2 server version of v38. When using a v40 instance, it should not be available from the app hub.