Unfortunately, the latest update did not resolve the issue. To provide an additional detail, I can confirm that the problem is specifically related to the "outline/bookmark" feature mentioned in the documentation. If the "outline/bookmark" is removed manually or via software before signing, the signing process completes without any issues, and subsequent signatures do not invalidate the previous ones.   I am unable to determine whether this issue originates from Adobe or the signing library, iText. Despite conducting several tests on the open-source version of iText, I have not been able to resolve the problem. For now, I am proceeding with a temporary workaround by removing the outline sections before signing.   P.S. : I am researching how other libraries handle this issue. It seems that the Java versions do not have this problem—likely because they correctly calculate the outline section and process it accordingly. However, the .NET version appears to be problematic. ... View more

- I couldn't find an edit - Although the topic is similar to this one, it seems independent, so I would appreciate it if you could move it to a topic like this: "A pdf document with a valid signature is marked as invalid because it was signed a second time or more." ... View more

First of all, thank you for replying to my message.   I would like to upload a sample document, but since it will contain my personal signature, I do not prefer to share it on this platform. If there is a corporate bug notification or tracking environment, I can share it there.   On the other hand, practically and legally, it should be guaranteed that no changes can be made to a signed document, if they are made, the signature becomes invalid, but in this case, the opposite is true. If an invalid document - as you mentioned, is fixed when annotated - becomes valid with editing, which means a serious problem. If there is a bug in the background, then signed documents can be manipulated in some way, which means a transition from bug level to security vulnerability level.   As a result, when I analyze the PDF document (with Itext's RUPS software), there is a difference between the "unvalidated" status and the "validated" status. (When Validate is used, it asks you to save the document, and from here it can be understood that a change has been made)   I can see the exact change with the WinMerge tool. I added an image of the changed part in the attachment (yellow area), then the object data related to the user, which is already in the document, was added. Frankly, I'm confused... ... View more

Hello, I would like to share some information regarding this issue. I am a developer working on e-signature applications, and my applications, which have been running without any issues for a long time, suddenly started throwing errors. It took a while to understand the root cause because, while all other applications recognized the signatures as valid, Adobe Reader/Acrobat marked all signatures after the first one as invalid and only considered the last signature as valid. After extensive trial and error, I discovered that this issue occurs when a PDF is generated by merging multiple documents and at least one of those documents contains a comment or annotation. Once I identified the problem, the only workaround I could find was to open the affected PDF (where signatures are shown as invalid), add a comment to a  page, and then cancel it without filling it. Doing so prompts Adobe to revalidate the signatures, after which all signatures appear as valid. However, you must first manually click the Validate button for this to take effect. I believe this is a bug. Attached images (error_1, 2, 3, 4, 5) ... View more

Hello, I would like to share some information regarding this issue. I am a developer working on e-signature applications, and my applications, which have been running without any issues for a long time, suddenly started throwing errors. It took a while to understand the root cause because, while all other applications recognized the signatures as valid, Adobe Reader/Acrobat marked all signatures after the first one as invalid and only considered the last signature as valid. After extensive trial and error, I discovered that this issue occurs when a PDF is generated by merging multiple documents and at least one of those documents contains a comment or annotation. Once I identified the problem, the only workaround I could find was to open the affected PDF (where signatures are shown as invalid), add a comment to a  page, and then cancel it without filling it. Doing so prompts Adobe to revalidate the signatures, after which all signatures appear as valid. However, you must first manually click the Validate button for this to take effect. I believe this is a bug. Attached images (error_1, 2, 3, 4, 5) ... View more

Hello, I would like to share some information regarding this issue. I am a developer working on e-signature applications, and my applications, which have been running without any issues for a long time, suddenly started throwing errors. It took a while to understand the root cause because, while all other applications recognized the signatures as valid, Adobe Reader/Acrobat marked all signatures after the first one as invalid and only considered the last signature as valid. After extensive trial and error, I discovered that this issue occurs when a PDF is generated by merging multiple documents and at least one of those documents contains a comment or annotation. Once I identified the problem, the only workaround I could find was to open the affected PDF (where signatures are shown as invalid), add a comment to a  page, and then cancel it without filling it. Doing so prompts Adobe to revalidate the signatures, after which all signatures appear as valid. However, you must first manually click the Validate button for this to take effect. I believe this is a bug. Attached images (error_1, 2, 3, 4, 5) ... View more