Error Sending File to a User

[dmil]

I tried this
slackcli -t xxxx-xxx-xxx-xx -a -d @user --file filename.csv -m "message"

and this
slackcli -t xxxx-xxx-xxx-xx -a -d @user --file /full/path/to/file/filename.csv -m "message"

for both I get the following error

/usr/local/lib/node_modules/slack-cli/node_modules/form-data/lib/form_data.js:217`
var filename = options.filename || value.name || value.path;
^

TypeError: Cannot read property 'name' of undefined
at FormData._getContentDisposition (/usr/local/lib/node_modules/slack-cli/node_modules/form-data/lib/form_data.js:217:43)
at FormData._multiPartHeader (/usr/local/lib/node_modules/slack-cli/node_modules/form-data/lib/form_data.js:171:33)
at FormData.append (/usr/local/lib/node_modules/slack-cli/node_modules/form-data/lib/form_data.js:64:21)
at appendFormValue (/usr/local/lib/node_modules/slack-cli/node_modules/request/request.js:327:21)
at Request.init (/usr/local/lib/node_modules/slack-cli/node_modules/request/request.js:338:11)
at new Request (/usr/local/lib/node_modules/slack-cli/node_modules/request/request.js:128:8)
at request (/usr/local/lib/node_modules/slack-cli/node_modules/request/index.js:54:10)
at Function.post (/usr/local/lib/node_modules/slack-cli/node_modules/request/index.js:62:12)
at post (/usr/local/lib/node_modules/slack-cli/bin/cmd.js:124:24)
at Array.async.auto.uploadFile (/usr/local/lib/node_modules/slack-cli/bin/cmd.js:380:13)

[dmil]

Update: This is only an issue with sending message to a user, works fine if I send to a group

slackcli -t xxxx-xxx-xxx-xx -a -h group_name --file /full/path/to/file/filename.csv -m "message"

works fine. But messaging to a user still doesn't seem to work.