Software licensees in Europe can fix their software
The European Court of Justice ruled that lawful software licensees can decompile and correct errors in licensed object code, even when the licensor does not wish them to do so. This decompilation right however is limited to correcting errors.
Software licensors should therefore add contractual language governing the licensee's right to decompile.
Top System SA v. Belgian State, Case C-13/20 (ECJ, October 6, 2021).