The latest DSsignfile utility from Steam seems to have problems with at least one addon that I have been working with and produces bisign files that don't work and are rejected by Arma 3 as incorrect.
An earlier version of the same addon seems to work OK.
After lots of tries I eventually used an older version from arma2.com that was linked to in the forums, and the bisign file produced was correct.
Filesize of the one that doesn't work is 227,328
Filesize of the one that works correctly is 188,416
Copies of bisign files produced by both versions are in the attached zip file and are noticeably different even when opened with notepad ++.
Not sure if it is just a few addons that exhibit the issue or all of them. {F26772} {F26773} {F26774}