Image lightbox not working in subfolder install

[jomaxro (Joshua Rosenfeld)]

@vincentp

subfolder installation

Subfolder installs are notoriously difficult to configure. Hence the warning in the subfolder guide:

@neil

Discourse Official Statement about Subfolder setup

We support subfolder setups for our hosted customers at the enterprise level and up. Due to heavy technical setup complexity we strongly recommend you do not use this setup unless you are very experienced in custom subfolder setups.

Best guess, something is not configured correctly with your proxy.