TIA Portal v14 cannot go online with S7-1500

We have one problem with TIA Portal and S7-1500 PLCs, it is that every while during download we get download to device error and error that 'service is not started'. So far it happened 4 times in ~5 months on one PLC where more than one person is working.

After that we cannot access PLC with TIA Portal, we cannot go online with it. And more, it happens for all who try to access PLC, if someone gets this error communication cannot be established for ANYONE trying to access PLC with TIA Portal.

HMI-PLC communication continues normally, and execution of PLC program is normal. But programmers cannot access PLC until it is completely rebooted, basically we shut it down and restart it.
Putting PLC to stop and run or changing port from which you access and other methods we tried don't work.
Only complete shutdown.

Does anyone have any idea what this problem is? Next time we'll try to screenshot error and send it to Siemens, but it could take some time until we repeat it again.

Does anyone know has this error been already recognized and fixed by Siemens? Is it firmware problem or a bug inside TIA Portal?

It happened again, this time I managed to get screenshots.
Anyone ever got error like this?

https://i.imgur.com/OXUxyzk.png


https://i.imgur.com/aK48hhK.png

"It says communication to PLC was lost" have you checked your connection. Maybe you have loose connection. Maybe your Ethernet cabe needs to be replaced.

Have you tried Siemens support?

chopin said:

"It says communication to PLC was lost" have you checked your connection. Maybe you have loose connection. Maybe your Ethernet cabe needs to be replaced.

Have you tried Siemens support?

Click to expand...

Damn, of course we tried a lot of things, including that one. And this has happened to two different PLCs, on two different switches, in two different countries. But with same project running on both PLCs.
So either something in project is broken, or inside TIA Portal or in firmware on at least two PLCs (probably all PLCs).

We contacted support, hope they'll have some answers. We can't really upgrade firmware, we'd need TIA v15 for that...