MKR1000 crash during wifi interruption by timer interrupt

Hi all,

I have a Problem that my MKR1000 crashes during the wifi communication with a RP3 Server.
Basically the Programm works like this:
In the setup there are opened two sockets to the Server.
One is for the control (Start, Stop bits e.g.), the second is for the data transfer.

Once the start command is received at the MKR1000 side the following code will be processed:

A function with is running controlled by a Interrupt (like here: TimeOne Library for MKR1000? - MKR1000 - Arduino Forum). This function runs app. every 100 ┬Ásec. and 100 times.
After this 100 cycles a Array of 1200 Bytes is filled with values and will be send to the Server with the command Client.write(var,sizeof(var));

After a certain time the communication breakdown. When I run the Program with a running Serial Monitor I see that also the Monitor crashes. So I think maybe the MKR1000 crashes down.

The Interrupt handler like in the link above works fine. I tried it in a different sketch.
So I think about that the Problem is maybe on the Hardware side of the MKR1000. As i saw in the Atmel documentation there is a SPI Bus between the mc and the Wifi- chip.
Maybe the Interrupt function takes into account that the communication crashes ?

Or maybe the Problem can be on the RP3 side, that my python function is not able to clear the socket that fast ?
But I got no fault on the RP side. Only that I cannot run the skript anymore if the MKR1000 crashes.
In the wireshark I see also that there are no messages send anymore from the MKR1000.

I hope somebody has some experience with this issue and can give me some tips.

Best regards

Today I tried also the same with only sending a ping from the MKR1000 to the Server.
Also the Interrupt controlled function was running. this run for 2 h with out any Problem.

Maybe the problem is on the RP 3 side with the socket ?