A bad news is that the database of this blog seems to have been reverted to 3 years ago due to some technical problem. I have used 1and1 as hosting service for my websites for the last 10 years, but now it seems that the database for the blog was overwritten with an old backup because everything is as it was 3 years ago in January 2017. I have contacted 1and1 to try to fix the issue, but they denied that it is their fault and did not have any other backup to restore the database. And my own backup is a little bit old… This is unfortunate. Thus, I think that maybe all blog posts of the last three years are lost (maybe 50+ posts). Anyway, this can of things happen, and I will continue the blog again soon… But this time, I will not trust the hosting service and do my own backups more often.
I am now trying to recover old posts through the Internet Wayback Machine and the cache of web search engines… I have recovered a dozen posts already and will continue but it may take some time.
Update: After several hours, I think that I have recovered most of the missing blog posts… but maybe there are some broken links. At least, most of the posts are not lost.