Same result using latest version or 1.7 hotfix 2
Version:
Corona Renderer - Standalone, version: 2 DailyBuild Mar 21 2018
(c) Render Legion a.s., 2016
BUILD_DATE: Mar 21 2018 10:42:13, internal color space: Wide RGB
Ran
/Applications/CoronaStandalone.app/Contents/MacOS/libCoronaStandalone -mtlPreview
License info:
Demo license active.
Activated until: 2018-05-02
1.0 100 100 test.png <material class="Native"><diffuse><map class="Texture"><image>texture.jpg</image></map></diffuse></material>^@
ERROR: Fatal error in mtl-XML file: 'STDIN': Texture with file name: 'texture.jpg' not found/not accessible
^@ is the null character, you can enter it using <ctrl>+@ (for me <ctrl>+<shift>+2)
texture.jpg is definitely there and accessible, same issue running as root.