Question: I have encountered an issue with a document where I am cannot add a check mark from Fill & Sign.
In v12.x and prior version of Foxit PDF Editor, Fill & Sign tool is designed for filling "Plain form", meaning there’s not any interactive form field in the documents.
If there are interactive fields in the document, such as Text Field, then the Fill Text and Fill items in the Fill & Sign tab are grayed out and unavailable, unless the Sign function.
If use Apply All Signatures, all the interactive form will be flattened. That is, the Text Field mentioned above will be flattened, and then the Fill Text and Fill function items in the Fill & Sign tab will be available.
Since version 13.0 and 2023.2 Foxit PDF Editor,
The check mark option won't be grey out if editing an interactive form.