I, too, am experiencing this issue. I do not have any non-english characters in the path. I can see that, in the only log available to me, that UnityHub is trying to perform a read operation on a directory that I try to open. The following is the excerpt from ~/.config/UnityHub/logs/info-log.json:
{"moduleName":"EditorPrefLinux","level":"warn","message":"[ { Error: EISDIR: illegal operation on a directory, read errno: -21, code: 'EISDIR', syscall: 'read' } ]","timestamp":"2019-06-12T06:59:07.059Z"}
{"moduleName":"EditorPrefLinux","level":"warn","message":"[ { Error: EISDIR: illegal operation on a directory, read errno: -21, code: 'EISDIR', syscall: 'read' } ]","timestamp":"2019-06-12T06:59:07.060Z"}
I obtained this with tail -f ~/config/Unity/logs/info-log.json
and observing the new entries as they happen. The two entries above are the only entries that appear when opening a project.
In the end, I cannot open any of my projects, which stalls my work. Any attempts to open Unity itself and then open a project through the Editor brings me to Hub in a cruel circle. I have access to a laptop that I can work on in the meantime (exact same versions of exact same software packages) where this issue does not arise. Thankfully, this has allowed me to work, but a 2015 laptop with built-in GPU is not nearly as pleasant to work with as my Ryzen 2700 machine 
Are there other logs that I can look at to get a glimpse of what is going wrong? Is there an open bug report that I can attach logs to? As my client is paying for a Pro subscription, is there another avenue of help that I can explore to resolve this issue?
I am grateful for any help you can provide. I cannot attach a JSON file to this post, so I have uploaded the log to PasteBin: UnityHub Log - Pastebin.com
[EDIT] Here is a tidier log file UnityHub Log - Pastebin.com that is from a clean install of Unity Hub 2.0.1. Issue persists.