==== What is the problem?
Now that the Special:Block form uses `usersmultiselect` for user/IP input (since T324602), there are a few differences in the way user input is validated and the validation errors that are shown.
I have found so far:
- When you enter an invalid/non-existent username, the validation error is `Invalid IP address` at the top of the page. Previously, the validation error was `There is no user by the name "<invalid username>". Check your spelling.` next to the input field.
- If there are more than one validation errors, they do not all show up. This may just affect the user/IP input field, I have not been able to investigate further.
It seems possible that there are other differences, so we should try to find those as well.
==== Steps to reproduce problem
**First bullet point above:**
# Go to Special:Block
# Type in a non-existent username
# Enter an expiration date
# Submit
**Expected behavior:** Some sort of validation error informing you the user is invalid/non-existent.
**Observed behavior:** The validation message is "Invalid IP Address".
**Second bullet point above:**
# Go to Special:Block
# Enter an invalid username
# Select an expiration date from the dropdown
# Submit
# Then re-enter an invalid username
# Change the validation dropdown to "other time"
# Submit
==== Environment
**Wiki(s):** https://de.wikipedia.beta.wmflabs.org MediaWiki 1.41.0-alpha (cbd42f6) 14:04, 28 March 2023.
==== Screenshots
Invalid username **before** (local docker):
{F36931017}
Invalid username **after** (dewiki beta) (note that the username I had entered is cleared when the form reloads):
{F36931019}
Multiple validation errors **before**:
{F36931032}
Multiple validation errors **after**:
{F36931030}