A little theory
mappView client creates and stores a session cookie during startup to store some local information about the client. The current date and time is used for that with validation for 400 days. This opens the question of what will happen after those 400 days. The cookie must be renewed, which can be done:
- during the next mappView client startup
- starting from 5.24.5, is done automatically
Can I notice that?
Since this is done automatically, usually the user will not notice. But there is at least one special case where you might. When mappView client does not store local date (or the date and time on the NTP server is changed) . After a mappView client restart, the time has to be synchronized with the NTP server, and the difference is greater than 400 days. In this case, you have two options:
- Wait with starting the mappView client until the NTP time is synchronized (e.g. T50/T80 has configuration in service page for that).
- You can start the mappView client and operate it, but take into consideration that after time is synchronized, when a page navigation action is triggered, the mappView client will restart automatically to renew the cookie.
Possible errors
“Visualization already open on this client, no further sessions allowed”
…or…
“Server connection lost, trying to reconnect…”
In mapp View 6.5 was dedicated error message implemented
Since mapp View version 6.5.0, we improve the behavior by the following:
- Displaying an information on client side
- Allow the customer to start the visualization with an trigger button
- Create a log book entry on the server with a specific information about the time difference of Server and client
- Add additional info to the help
Key takeaway
- If your mappView client restarts shortly (time synchronization can take couple of minutes) after startup during operation, check the local time before you start investigating further.
As usual, hoping that it helps 
Jaroslav 
