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I am sorry to learn of this situation. While under traditional breach of contract and negligence theories you would be able to recover for these losses. (There would be some issues with the damages due to limitations on "speculative damages" (damages based on potential income or loss - you would have to overcome this by showing past history of rental, etc., which you probably could do)).
However, most software and computer database services have very thorough (albeit one sided) limitations on liability clauses (these clauses may have different names, or may be numbered) but will be part of your terms of service with the software company. The starting point (especially with a loss as large as this one) is to do a very detailed review of the contract itself, to see what limitations exist (if any) so that you can identify any clauses, and the extent - if the clause is sloppy or incomplete, you may still be able to bring your claim).
If your software company is like most, and their liability really is limited in this regard, you can still argue with them for refund of the cost of service (you shouldn't have to pay for services that you didn't receive, or received incompletely).