Can i return to eM Client 7

There are many problems with eM Client 8.

Normal I use the dutch version.So I changed to the English version to find the correct names for everything. But then my agenda was totally empty. No problem I can restore all data. Oh. There is no restore function only a backup function. Bye bye agenda?
Tents of times a day on my screen appears a message witch covers parts of my screen. See picture if it was posible. You could WATCH THE DATES of the message.
When I open the windows new message I see a lot of very old alarms en also a lot of alarms in a far future. See picture.if it was posible

So eM Client is far from ready and I hope I can return to version 7

Yes you can.

I think one thing that demonstrates how seriious the problems with v8 are is that eM Client themselves have posted a guide here in their knowledgebase. The real issue is losing the ability to get at a saved database once it’s migrated from v7 to v8. It’s probably lost unless you made back-ups of the v7 version.

(Personally I just use eM Client to manage an online account with all settings on server, so nothing much to lose for me - I can just re-sync the data to the new installation.)

I’ve also tried to spell out how I did a clean install once or twice on this forum. See here for the most comprehensive. I hope you can find a suitable Nederlandse version of v7 to reinstall.

since some users were requesting it, we provided steps on how to downgrade here -

As for your reported problems - the change of language should not remove any data, can you provide more details on what happened?
Also, restore function can be found in Menu>File>Restore, same as was in eM Client 7.
If you want to stick with eM Client 8, please do try the latest update -