moving a plan from project A to project B does not rename the build log files.
./xml-data/builds/A-HEAD/download-data/build_logs/A-HEAD-1.log
is moved to
./xml-data/builds/B-HEAD/download-data/build_logs/A-HEAD-1.log
the UI tries to link to download/B-HEAD/build_logs/B-HEAD-1.log
and throws an exception.