JAM Software, the maker of the disk space analyser TreeSize, has angered some customers by declining to renew updates or support for perpetual licences once their initial maintenance period expires, unless they switch to a subscription. The company has also drawn criticism for its long-standing policy of not supplying license keys or installers to perpetual licence holders after that support window closes, leaving customers who fail to back up their own files locked out of reinstalling software they already own.

Since 2025, JAM Software has moved most TreeSize editions to a subscription model, now selling perpetual licences only for personal use, bundled with 12 months of updates and support that can optionally be extended. Product manager Hendrik Christ said the change was necessary given "current economic conditions" to sustain long-term development, and defended withholding old installers and keys as a security measure, since outdated versions can carry unpatched vulnerabilities. He rejected calls for refunds, arguing customers retain indefinite use of the version they bought, though he acknowledged the shift has proven "frustrating for some customers" amid a free alternative, WinDirStat, and a limited free TreeSize edition lacking business features.