Can a divorce still be filed If a party is unwilling to cooperate?

If a party is unwilling to cooperate, the best option may be to commence a court application. Your fiancée can ask the court to make an order for the divorce, along with orders dealing with corollary relief issues (ie. property division, support, etc.) which would have been dealt with in the separation agreement. Once a court application has been commenced, the parties still have an opportunity to reach an agreement, but starting a court proceeding will require your fiancee’s ex to deal with the issues and will impose timelines for doing so. If there is an urgency to obtaining the divorce order, it can be obtained before the other corollary issues are settled by including in the application a request for an order severing the corollary relief issues from the divorce. This will allow your fiancée to proceed with obtaining the divorce before dealing with the other issues. However, obtaining a divorce before all of the other issues are settled may affect how those issues can be dealt with later. I would strongly recommend that your fiancée speak to a lawyer in more detail about the issues involved in his specific case.