tracks missing when multiple exporting

I have a project of about one hour and 21 tracks.
When I export the files in WAV using multiple export, 2 tracks are not exported, only 1 second.
However, these 2 tracks are not missing when I export the whole project as a WAV file.
Why is that and how can this problem be remedied?


Can you repost your query under the proper category according to stable or beta, and then under your operating system. The people that frequent those categories will be better adept at answering your query.