Article 5(1) of Council Directive 91/250/EEC of 14 May 1991 on the legal protection of computer programs must be interpreted as meaning that the lawful purchaser of a computer program is entitled to decompile all or part of that program in order to correct errors affecting its operation, including where the correction consists in disabling a function that is affecting the proper operation of the application of which that program forms a part.
Article 5(1) of Directive 91/250 must be interpreted as meaning that the lawful purchaser of a computer program who wishes to decompile that program in order to correct errors affecting the operation thereof is not required to satisfy the requirements laid down in Article 6 of that directive. However, that purchaser is entitled to carry out such a decompilation only to the extent necessary to effect that correction and in compliance, where appropriate, with the conditions laid down in the contract with the holder of the copyright in that program.
Article 5(3) of Directive 91/250 must be interpreted as meaning that a person who has obtained a copy of a computer program under a licence is entitled, without the authorisation of the owner of the copyright, to observe, study or test the functioning of that program so as to determine the ideas and principles which underlie any element of the program, in the case where that person carries out acts covered by that licence and acts of loading and running necessary for the use of the computer program, and on condition that that person does not infringe the exclusive rights of the owner of the copyright in that program.