Gallery photos not showing up in the WordPress Car Dealer plugin

I have uploaded images and inserted them, but they are not showing in the frontend of the post. However, they are showing in the HTML. It looks like there is an AJAX error.
09a1e2f27968993afb2b69e16e71ca22.js:3 Uncaught Error: Fatal error: No theme found.
at Function.Galleria.raise (09a1e2f27968993afb2b69e16e71ca22.js:3)
at 09a1e2f27968993afb2b69e16e71ca22.js:2
Galleria.raise @ 09a1e2f27968993afb2b69e16e71ca22.js:3
(anonymous) @ 09a1e2f27968993afb2b69e16e71ca22.js:2
setTimeout (async)
add @ 09a1e2f27968993afb2b69e16e71ca22.js:2
addTimer @ 09a1e2f27968993afb2b69e16e71ca22.js:2
init @ 09a1e2f27968993afb2b69e16e71ca22.js:2
(anonymous) @ 09a1e2f27968993afb2b69e16e71ca22.js:3
each @ jquery.js?ver=1.12.4:2
each @ jquery.js?ver=1.12.4:2
t.fn.galleria @ 09a1e2f27968993afb2b69e16e71ca22.js:3
(anonymous) @ ae5927c9e2f30eca7b3559d1689cc15c-1.js:2
i @ jquery.js?ver=1.12.4:2
fireWith @ jquery.js?ver=1.12.4:2
ready @ jquery.js?ver=1.12.4:2
K @ jquery.js?ver=1.12.4:2