Troubleshooting: Cannot read the array length

The following exception report relates to pulling the list of files from a local directory:

com.minisoft.Director.LocalQueueMonitor::a:-1 Cannot read the array length because "" is null

The most likely cause is a misspelled directory name. Depending on the operating system, this can also be caused by differences in capitalization. Generally, security and permissions will generate a different message. However, this may still be seen for some systems.