My company had to pull me off of my current contract and pay a considerable amount of overtime to address an Oracle issue that turned out to be due to the customer's unwillingness to pay the huge cost of and Oracle DBA to maintain this abomination.

In another instance our customer was paying big time for some Java web based reporting software but when the navy pushed the next edition of the Java JRE, it was so non-backwards compatibile, that the software stopped working and it would have require almost as much a cost to for the company that made the software to upgrade it as it cost originally. They had to maintain one machine with the older JRE in order to retain access to all their reports.