# AttributeError: 'NoneType' object has no attribute 'get'

## What happened

Issue chroma-core/chroma#2510 (closed, 19 comments): ### What happened? I have installed latest version of chroma 0.5.4 using pip in python language I am connecting to my chroma set up in an AWS EC2 instance through docker installation method. After creating a connection through chroma HttpClient using the host address and port name I tried to get list of all my connections using the below code: collections= chroma_client.list_collections() and it is throwing the following error AttributeError: 'NoneType' object has no attribute 'get' I downgraded my chroma to version 0.5.3 and it was working fine Seems like an issue with newer version of 0.5.

## What works

This is almost always a client/server version mismatch. Check which Chroma server you are talking to and install the matching client version, or upgrade both together. Mixing a new client with an old server (or vice versa) is what produces the NoneType error.

## Caveats

This comes from one real issue thread (gh:chroma-core/chroma#2510); it is the verified fix or approach from that thread, not a general manual. Check your version of Chroma first ,  maintainers often fix the underlying bug in a later release, and the thread may predate it.