Can't use localhost:8545 or 127.0.0.1:8545 as endpoint

[jonpurdy]

Tested the following:
✓ const URL="http://138.197.193.189:8545"
✓ const URL="http://fs-trex0.jonp.ca"
✓ const URL="https://fs-trex0.jonp.ca"
✕ const URL="http://localhost:8545"
✕ const URL="http://127.0.0.1:8545"

See error.log for details:
error.log

Running geth:
geth --syncmode light --cache=4096 --rpc --rpcaddr '0.0.0.0' --rpcvhosts=*

If this works for you, close the issue and I can debug further on my end.