1. General questions

After changing the License Key or adding a new paid extension to existing License Key, extensions must be downloaded automatically. If not, a notice will appear on the WP Plugins tab that an update is required for the E2Pdf plugin. Update the plugin to install the new extensions.
To upload new fonts go to E2Pdf -> Settings -> Fonts. After successfull upload font will appear in the "Font Dropdown" in templates.
At this moment, fields are fully recreated and controlled by E2Pdf. To use the original font, you must upload the font to E2Pdf and assign it to the PDF form field(s), or any other created objects from the PDF Builder.
To use E2Pdf with 3rd party plugins you must use paid License Key with its supported extension.

So be sure that you have included 3rd party extensions among purchasing License Key, if not, you can just "UPGRADE" your License Key from Dashboard -> Licenses or purchase needed at Extensions list.
Go to "E2Pdf -> License". Click "Change". Leave field empty and click "Submit".

Website License Key will be dropped to "FREE" License Key.

Note: If you have more than 1 activated templates, you must deactivate them before this action as "FREE" License Key allows only 1 active template.
Check please if checkbox option doesn't contain any commas. If so, you will need to build the form with the way to avoid commas inside option.

Solution for Formidable Forms:
- Use "Use separate values" with checkboxes. Set "Saved value" for each checkbox without any comma and map field inside E2Pdf template with:
Value: [field_id show='value']
Option: Saved Value
There are 2 ways to map fields:

Auto mapping with Visual Mapper:
Right mouse click on E2Pdf element (input, checkbox, select, etc) -> Map field -> Click on needed Element. It will be mapped automatically.

Manual mapping:
Right mouse click on E2Pdf element (input, checkbox, select, etc) -> Properties. There you can set value and other options depending on element type.