[bambuko]

Thank you!
I have run it as user (it started fine) but these were the messages in terminal:

/media/995de026-70b2-4991-a641-eb0067f25a5a/calibre-portable.sh: line 113: $(pwd)/calibre-portable.conf: Permission denied
CONFIG FILES:       /media/995de026-70b2-4991-a641-eb0067f25a5a/CalibreConfig
--------------------------------------------------
LIBRARY FILES:      /media/995de026-70b2-4991-a641-eb0067f25a5a/CalibreLibrary
--------------------------------------------------
SOURCE FILES:       *** Not being Used ***
--------------------------------------------------
PROGRAM FILES:      /media/995de026-70b2-4991-a641-eb0067f25a5a/calibre
--------------------------------------------------
TEMPORARY FILES:    /tmp/CALIBRE_TEMP_yI74c0m
--------------------------------------------------

Press CTRL-C if you do not want to continue
Press ENTER to continue and start Calibre

Starting up Calibre from portable directory "/media/995de026-70b2-4991-a641-eb0067f25a5a"
Using library at /media/995de026-70b2-4991-a641-eb0067f25a5a/CalibreLibrary
Failed to initialize plugin: ISBNDB (1, 0, 0)
Failed to initialize plugin: <class 'calibre.ebooks.metadata.sources.isbndb.ISBNDB'>
Exception in thread Thread-1:
Traceback (most recent call last):
  File "threading.py", line 810, in __bootstrap_inner
  File "site-packages/calibre/utils/fonts/scanner.py", line 231, in run
  File "site-packages/calibre/utils/fonts/scanner.py", line 280, in do_scan
  File "site-packages/calibre/utils/fonts/scanner.py", line 350, in write_cache
  File "site-packages/calibre/utils/config.py", line 363, in __exit__
  File "site-packages/calibre/utils/config.py", line 352, in commit
  File "site-packages/calibre/utils/lock.py", line 139, in __enter__
  File "site-packages/calibre/utils/lock.py", line 118, in unix_open
OSError: [Errno 13] Permission denied: '/media/995de026-70b2-4991-a641-eb0067f25a5a/CalibreConfig/fonts/scanner_cache.json'

libpng warning: iCCP: Not recognizing known sRGB profile that has been edited

and... running as root:

CONFIG FILES:       /media/995de026-70b2-4991-a641-eb0067f25a5a/CalibreConfig
--------------------------------------------------
LIBRARY FILES:      /media/995de026-70b2-4991-a641-eb0067f25a5a/CalibreLibrary
--------------------------------------------------
SOURCE FILES:       *** Not being Used ***
--------------------------------------------------
PROGRAM FILES:      /media/995de026-70b2-4991-a641-eb0067f25a5a/calibre
--------------------------------------------------
TEMPORARY FILES:    /tmp/CALIBRE_TEMP_48ekKrq
--------------------------------------------------

Press CTRL-C if you do not want to continue
Press ENTER to continue and start Calibre

Starting up Calibre from portable directory "/media/995de026-70b2-4991-a641-eb0067f25a5a"
Using library at /media/995de026-70b2-4991-a641-eb0067f25a5a/CalibreLibrary
libpng warning: iCCP: Not recognizing known sRGB profile that has been edited

...Do you think it is easier to see what settings there are now? ...

Yes, I think this is an improvement!