There is a known issue which prevents the reset password page from working with Safari. If you receive the 'Reset password token is invalid' message, it is because Safari is autocompleting a (hidden) field on the page.
To resolve the issue, try one of the following courses of action:
1) Temporarily disable Safari autofill. Click the 'Safari' menu at the top of the page, then 'Preferences'. Click on the 'Autofill' tab in the Preferences window. Click on each of the check boxes next to the autofill options to deselect them, turning off the autocomplete for each option. Then, refresh the page and reset your password as usual. You can re-enable autofill after this step.
2) Copy the reset password link in the email. Open it in Chrome or another browser to reset your password.
Please email firstname.lastname@example.org if you continue to have issues.