As it turns out in version 4.6 all the module files were corrupted. I have corrected these in 4.6.1. Existing installations won’t have this issue as they already have the correct modules in their user folder.
If you downloaded Data Crow previously and you experienced this issue, please first remove the modules folder from the Data Crow user folder you selected when installing the product. Install version 4.6.1 and all should be fine.