Data Mismatch

Hey rispian​, try deleting squad updates and downloading them again from the game menu. This should help fix this error. You can also build a new squad, using different players and then try again. 

Its works but then it happened again and again,does this also can happend because of my internet connection?

Ensure you install all updates using a stable connection, preferably an Ethernet cable. For the best online experience, it's recommended to use a cable connection whenever possible.