SignField error

I'm trying to sign a signature field using the SignField method, but I'm receiving a -1 error code on return.
What does -1 mean?
I have the .p12 file inside the android device and I'm passing it's path to the second param (cert_file param). Is that wrong?
How should I pass this param to the method?

dear user, return value -1 mean one of following reasons:
1. no premium license actived.
2. document is not writable. this can be checked by Document.CanSave();
3. the native library that you are using not support signature
for arm64, library support signature has size 4.7M, and 3.7M for library without signature feature
4. password of cert file is null.

other return value will be:
-2: annotation is not sign field or field has already signed.
-3: invalid annotation data.
-4: save PDF file failed, this shall be rarely. most like memory allocate failed and other system error.
-5: cert file open failed.

I see.
Well, after debugging and some tests, I think it might be number 3.
How can I know the size of my signature support library?

dear user:
please download this demo:
www.radaeepdf.com/download/download-prev...4-radaeepdf-3-54beta
this demo integrated sign feature into reader(only opengl rendering mode).
you can sign the field by single tap on empty signature field.
when single tap on an empty signature field, a sign dialog shall be displayed.

Hi. Thanks for the version!
I just tested, but I'm having an issue.

After signing the document and opening it on Acrobat Reader, it tells me the signatures need validation.
And when I click in one of the signature fields, I receive the a warning mess age.

I'll attach the messages and errors.
Let me know if you need more info.

about validate signature: please check whether cert file is out of date, that make signature invalid.
about your error information: not happen for my version (tested on Acrobat pro X).

we will update a new version which can set signer name for method Annotation.SignField();
the attachment is a signed pdf that using Annotation.SignField();