Thank you. I have had an further email from them telling me that their client will be in touch to discuss the matter....

Have just received a letter from CJCH solicitors claiming my company has been using a cracked copy of Solidworks 2017. We have 3 paid for seat of Solidworks 2015 and have never used either a legal or cracked version of Solidworks 2017. CJCH have said they are going to send me the MAC addresses of the computers that have used the cracked version. After discussion with my design team one of them has imported a couple of model files that were created on a cracked version of SW2017, these models were sent to us from a factory that we use to manufacture product in China. Any advise from anyone please :- 1 - Will opening a model made on cracked version of SW2017 have flagged up to them as if we had a cracked copy on our network? 2 - Is it infringement of copyright to open a file created on a cracked version? 3 - Do I just tell them one of our factories sent us a file that we opened and that we have since found out it was created from a cracked version of SW2017 and that they have no claim against us? Any advise gratefully accepted.