Present tense

Present tense is easier to read and understand than past or future tense. And simple verbs are easier to understand than complex verbs, such as those in the progressive or perfect tense. Remember that most (all?) users read while in the middle of a procedure. They're trying to troubleshoot or fix a problem. I've yet to meet a user who reads the documentation for fun.

Especially for procedures, think of the user as they follow the steps --- they're "in the now."

As you work, iPaaS warns you of potential errors.

instead of

While working, iPaaS will stop if you have made an error.