# ValueError: unknown channel A.TSLA (you may need to specify the right data\_stream)

**URL:** <https://forum.alpaca.markets/t/valueerror-unknown-channel-a-tsla-you-may-need-to-specify-the-right-data-stream/1424>\
**Category:** Alpaca Questions\
**Created:** [May 11, 2020, 2:51pm UTC](https://forum.alpaca.markets/t/valueerror-unknown-channel-a-tsla-you-may-need-to-specify-the-right-data-stream/1424 "2020-05-11T14:51:30Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![hitoshi](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.alpaca.markets/hitoshi/32/69_2.png) [@hitoshi](https://forum.alpaca.markets/u/hitoshi)\
**Post date:** [May 19, 2020, 6:50pm UTC](https://forum.alpaca.markets/t/valueerror-unknown-channel-a-tsla-you-may-need-to-specify-the-right-data-stream/1424/3 "2020-05-19T18:50:06Z")

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There was a change in SDK that now defaults to alpaca data stream unless you specify data\_stream parameter to the initializer, and alpaca data stream does not support A channel. That is what the error message means but apparently it is still not clear.

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_[View the full topic](https://forum.alpaca.markets/t/valueerror-unknown-channel-a-tsla-you-may-need-to-specify-the-right-data-stream/1424)._