TE_SL_TOO_SMALL

This error is from your exchange, in this case it appears to be phemex.
This particular error is because your Stop Loss amount is too small. You can see it says:
"TE" for Trade Error
"SL" for Stop Loss
"TOO_SMALL" - its too low, or out of range.

Here is a link to all of their errors for future reference
https://github.com/phemex/phemex-api-docs/blob/master/TradingErrorCode.md

We are working on implementing a more unified error message system but for now we are forwarding most messages through from your exchange. So any future issues should be easy to track down with the above link. 

Usually this error means you need to take a look at your stop loss and make sure it is in a predictable range. Some exchanges do not allow stop losses too far or close to an entry or current price.

Troubleshooting

To understand what stop loss price is being sent to the exchange you can follow the directions below:

Open My Strategies
Click Monitor on the strategy that is failing - (brings you to Strategy Monitor)
Then look for a failed trade in the table - Click on the timestamp link.
This brings you to the Trade Monitor page.
At the top there is a horizontal portion of the screen call the timeline, where you can see what events triggered this orders entry and exit.
In some cases depending on the error, this section may be lacking information or be completely empty.
In most cases you should be able to find a block that says Trade Open Request, and expand it. It should show you exactly what we sent to the exchange.
You can paste that in a reply which will help as well. This can also help you learn to trouble shoot if you are interested.

You can see an example of the Trade Open Request below. You may have to scroll to the right.