ProjectVersion error at bootup

Hello,

Since i've installed and upgraded to 2018.2.9, i always get an error message after booting up unity's editor :

Unable to parse file ProjectSettings/ProjectVersion.txt: [mapping values are not allowed in this context] at line 1

This happens for every version i've installed since, even with the latest stable 2018.3 and even with the alpha 2019.1.

I'm not sure what the problem is but so far the only possible consequence i can attribute possibly to this error is that one peculiar project never stays in the hub. Each time i relaunch the hub, the project i opened trough the hub is not in the recent list. Other than that, everything else seems unaffected by the error.

Edit : not sure if relevant, but the error message appears 4 times after the bootup. Not at different time, all 4 are present when the boot is finished.