Arduino ide did work only with root account

I had a problem. Linux mentality is to use ROOT account only when needed, not in every day use. I had to use ROOT account with arduino ide because I couldn’t upload sketch with normal user account. After several years I did manage to do something about it.

I did find same advice several times, but adding my user name to dialout group did not help. This is from arduinos own page.

sudo usermod -a -G dialout <username> 

After long googling I did find a solution. Old setting file. I have updated arduino IDE several times over the years and because I use ubuntu, my home directory has followed me years and over multiple computers. I don’t know what was the reason inside of file, but deleting .arduino/preferences.txt did work! (As instructed here.)

rm ~/.arduino/preferences.txt

Close arduino IDE before deleting! IDE will ask questions when you start it next time, but at least my in case it started working!

Edit: Also be warned that from ubuntu repositorys you get old version of arduino ide. Download it from pages!