Submodules don't display and git submodule command gets error

Source Tree has stopped displaying my submodules. When I go into terminal and type:
git submodule status
i get:
bash.exe: warning: could not find /tmp, please create!
C:\Users\David\AppData\Local\Atlassian\SourceTree\git_local/libexec/git-core\git-submodule: line 159: /usr/bin/perl: No such file or directory