Custom field blocks visibility on my project tasks

Hi All,
I accidentally added a custom field to my project when I was using the trial version.
Now that the trial has ended, my project has become inaccessible because of this custom field.
How can I remove this custom field and regain access to the project without a paid plan?

@Tommaso6,

Sorry to hear that. See my answer to a very similar question here:

Thanks,

Larry