The controller was unreacheable

Bernd shared this question 4 months ago
Need Answer

We have been on a short trip for 3 days. When leaving home the alarmsystem was armed.

After return I recognized three messages "The controller was unreacheable" at different times with the consequence that no rules were executed during our absence,

Can anybody explain to me what this message means, eventually what are the reasons for it and how to avoid it ?