Hi there! I understand you're having trouble logging into the AMC app and receiving an "invalid form submission" message, despite having the correct password. Let’s see if we can sort this out together.

Here are a few steps you can try to resolve the issue:

1. Clear Cache and Cookies: Sometimes, old data can cause login issues. You can clear your browser's cache and cookies by going to Safari > Preferences > Privacy > Manage Website Data, and then removing the data related to the AMC app.

2. Incognito Mode: Try accessing the app in an incognito/private window. This mode doesn’t use existing cache or cookies, which may help bypass the issue.

3. Check for App Updates: Ensure that you have the latest version of the AMC app installed. Sometimes, bugs are fixed in newer versions. You can check this via the App Store.

4. Reboot Your Device: Sometimes, a simple reboot can resolve various glitches. Please restart your Mac and try logging in again.

5. Try the Website: If you are able to log in via the AMC website but not the app, there might be a temporary issue with the app itself. You can report this to AMC support.

If these steps don’t resolve your issue, please let me know, and we can delve deeper or consider reaching out to support directly at [email protected] for personalized assistance.

Are you satisfied with the solutions I provided?