According to the information you provided us with, you use 1C:Enterprise platform 8.3.12.1440 and 1C:Enterprise mobile platform 8.3.11.61. In other words, one platform has the 8.3.12 major version, another platform has the 8.3.11 major version.
You should use the platforms having the same major version: 8.3.11 or 8.3.12.