I see references to this type of error being caused by a bug which was present in beta versions of Xcode 11, although there they were experiencing the error when using the iOS simulator and not Mac software. It doesn't say if or in what version the bug was fixed.
Did you build pgAdmin3 on your own computer (if so, which version of Xcode did you have when you built it?) or did you get our binary (which was built with Xcode 10.3)?
If you built it yourself and you have Xcode 11, make sure it's 11.2.1, the last version compatible with Mojave. (If it was an earlier Xcode 11, upgrade to 11.2.1, then rebuild pgAdmin3 from source using sudo port -ns upgrade --force pgAdmin3
.) If that doesn't work, try using our binary (sudo port -nb upgrade --force pgAdmin3
) or downgrading to Xcode 10.3 before rebuilding from source.
If you got our binary and it has the problem, then try rebuilding from source (sudo port -ns upgrade --force pgAdmin3
) with Xcode 11.2.1 installed.