When you perform a DataPlus import, you get the following message: Unable to process company. Reason given was: The company name cannot be empty.

When you create a company record in Act the Company field is required.

When you perform an import the likely cause of the error is a Company record was deleted. When DataPlus imports a company, it performs a date check. If the company was already imported, then the record is skipped. More import records are imported for the company, and it cannot find the company record, nor can it create it because there is no company name.

Run import with "Skip Date Check" checked.