Ruined my contacts.
Luckily I only seemed to need between two to three hours of sleep.
Reminded me to make a back-up.
Why not install Skype again, I thought yesterday. And only seconds after I had it installed on my Smart-Phone it showed me an error message. Something about android-process-acore messed up. Doubt if that was really the case though, it seemed more like Skype fucked up my mobile. Searched the world wide web, found the answer, well a possible answer. One 'solution' was to reset it to factory standards. Wut!? Being used to working in Linux that was a weird way to fix this. That would be like installing a complete Operating System again, to fix just one apparent error. It is like using a cruise-missile to kill a fly. All data cleared, all contacts gone into oblivion, no way...
Something with clearing 'cache' memory. Well, that did not really fix it. It was 'contact' related, removed a certain contact storage part. No more errors and no more editing the contact-list. Next thing to do was to remove the Contact-list data, that should help. All data gone, so now there were only phone-numbers visible in some messenger applications. Had saved the contact-list somewhere, last time june 2018 so at least most of it could be restored. At my Google account it seemed there was no data anymore, nor on my SIM card. And even though I had performed all the right steps activating the Contact-storage part seemed to trigger the error again.
Repeated the steps again. Then read somewhere to turn off the mobile and wait a couple of minutes before restarting it again. Great no error message anymore! Starting up Whatsapp and Telegram, nice, still okay. The WhatsApp screen flashed a couple of times, noticed how it was updating the contacts between every flash. Even my Google account contactlist seemed to be restored. While I do not really have a clue what fixed it, I'm glad that it was. After a short night sleep and a bad gut feeling this is at least a good thing. And I'm banning Skype, for ever.
Have a great one!
Android almost driving me nuts.

Image license CC0.
Edit: change image license.