CAUSE 1: Two different versions of Microsoft Excel are installed on the machine. For example, both 2010 and 2013 are installed.
CAUSE 2: Macro contained a combination of Macro recording and manual vbscript entries. Toad was unable to parse the manual scripting
RESOLUTION 1: Uninstall one of the versions of Excel, so only one version of Excel is installed on the machine.
RESOLUTION 2: Where possible, try to use the macro record to replicate the steps