Steps:

1. Go to Commerce/Payment methods
2. Click Create
3. Select language/Type and click Create 
4. Put a very long string to the Name and Identifier field
5. Click Create 

Actual result:

Alert message is displayed, but it can be really long so it covers Create and Cancel buttons and user is unable to close it. No field validation displayed. See attachment, please.

Expected result:

Field validation should be displayed. Alert message should be consistent with the message displayed in the same situation but for creating for example Product Type.