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Task is the main thread, I have two other threads that will emit the signal, one to call the slot log and the other one to call clog. while the signal to call the slot activity it's in the main thread.

The think it's that the log it's call every minute and the clog it's call also every minute, but a minute after log it's call. The problem it's that the activity it's call every 20 seconds, and if log o clog are call at the same time as the activity the api can't handle both request and one of the request it's end returning a null pointer.

I don't know if this explain the problem better. I'll try with the QMutexLocker.

Thanks

@koahnig @Chris-Kawa @swegmann
We switched on a more sensible connection handling system about 8 hours ago.

If you still see these events, please tell here immediately (because we really hope this would fix a lot of the problems we have seen).