There are new limits for keywords and negative keywords in Yandex.Direct. The previous limit for an ad group was 4096 characters. This limit — 4096 characters — is no longer applied to the whole group, but instead to each keyword and its negative keywords. In addition, you will be able to add up to 200 keywords to each group.
The limits apply when using the interface, and when managing campaigns using Direct Commander, the API, and file imports.