- In this version, abusefilter has 2 tags: "test" and "test2".
- Remove "test2" from "Tags to apply" box. There is only one tags "test".
- Click "Save filter".
- The change is not be saved.
If I make another change at the same time, ex. leave some message in "Notes" box. It can be saved.
There are the same bugs in zh.wikipedia.org and zh.wikipedia.beta.wmflabs.org.