All my old messages disappeared

Dear Sir,

Thanks in advance for any help !!

I´m using EM Client so many time ago but I’ve opened it this morning and noticed a lot of my messages in my folders on my PC have disappeared, only remains the folders empties.
I tried to restore from a backup made on January 2020 but it didn´t restore anyone an System gave this message I attached.

At least my full historic messages from the last 5 years yhat U copied to my PC were gone. Where did they go?. I cant find them.

Does anyone have any idea what’s happed and[date=2020-07-03 timezone=“America/Argentina/Buenos_Aires”] how to get my emails back?
Please help.
THANK YOU.