Unable to send mail

[webbird]

A customer asked me for help, don't know if this is used in the Ducksell core or a plugin. Here's the stack trace:

Exception: Symfony\Component\Debug\Exception\FatalErrorException

Declaration of Wpb\StringBladeCompiler\StringView::render(?Closure $callback = NULL) must be compatible with Illuminate\View\View::render(?callable $callback = NULL)
Trace:
#0 {main}

I digged into it and realized that the master branch is quite old and current version of that dependency does no longer have a render() method, so, as a "quick and dirty hack", I asked her to replace Closure with callable.

[webbird]

There's another one:

Declaration of Wpb\StringBladeCompiler\Compilers\StringBladeCompiler::compile($path) must be compatible with Illuminate\View\Compilers\BladeCompiler::compile($path = NULL)
Trace:
#0 {main}

After changing both it seems to work.