replace typing by isinstance, fix typos, add try/except section in sensitive area
replace typing by isinstance, fix typos, add try/except section in sensitive area

git-svn-id: ee7a57951e762bd0bd73821a456cc95fa2e543d2@4560 1105ee14-b0fa-0310-85a5-ff3eed429ff7

umitproject/umpa,umitproject/umpa