Hi good people,
every time now when I turn on the pro timer it says "RTC is not running, please wait" and every time it asks to set the time and the day.

What can I do?
Thanks

The button cell battery that powers the real time clock is out of juice and needs to be replaced. This is normal every 2 or 3 years.
Check out the manual where you can find how to exchange it (end of page): https://lrtimelapse.com/lrtpt/manual/

Thanks so much, already ordered

I've changed the text of this message to more descriptive in Firmware 30: https://lrtimelapse.com/lrtpt/firmware-updates/