If you get a signature error for some section of the tachograph file:

You need to check out the tachograph in a service if you encounter this problem. The tachograph probably needs to be replaced.

You can make a manual download from the tachograph and the program will skip the signature error parts of the Detailed Speed and the Technical Data or it will download until the first occurrence of the signature error in the activities. Then make another download to skip the signature error day.

In our example the signature error is on day 2017-09-10, so make a manual download from the last download date until 2017-09-09 and after complete start the next download from the date 2017-09-11.

Keep in mind that the days that have signature errors won't be downloaded that can cause problem with the authorities.