With the WWDR certificate expired this weekend, users run into issues replacing it. When they add it to the login (which for me is default) keychain Titanium does not find it. It must be in the System keychain to be found.
This Stack Overflow user found out where the bug is:
I've tested this and indeed this fixes it.
PRs are attached.
This is critical due to the WWDR expiration and must be merged for 5.2.0
I've added a note to this blog post: