Robert Covington wrote:

> "Warning:Could not create .dSYM file"
> Maybe it is something I can't do, or shouldn't be doing, but when I select UB architecture and 10.4 for both deploy and features, I get that error there (UB being the apparent causal factor). The compile fails.
> 
> v5.4.5


It means that the dsymutil tool reported an error during the build. Without more details of your Mac and FB project I can't guess why it failed.

If you turn off the settings checkbox 'Put line # info in app', FBtoC won't invoke dsymutil. That should fix the warning.
Hover the mouse over the checkbox to see the help info.

Robert P.