hello! i’ve currently been having this same issue that others have previously made posts on: when opening krita i am hit with a message that says “there are no brush presets available”.
i believe i have tried every method shared so far in each thread to no avail. however, i am making this post to provide some new information on the issue if it will help any developers fix it 
- i didn’t have this issue when i had krita 5.2 (or so?? i apologise i don’t remember the exact version) on my old laptop. i only recently started having this issue when i downloaded 5.3.2 on my new laptop on windows 11.
- i updated to 5.3.3 recently and still have the issue
- afterwards i decided to switch to krita 6.0.3 (i don’t know much about the differences between the two versions) but i still have this issue
- on a fresh install of krita, the message doesn’t pop up. after 5 or 6 sessions of starting up krita, i get the message. i found this out when i uninstalled and deleted krita, and reinstalled it from the website
- on occassion i can bypass the message by repeatedly opening up a .kra file, then closing the program. after 5 or so tries my brushes are available to use.
- i have tried to delete or rename the resourcecache.sqlite file as mentioned in previous posts but the message still shows.
sorry if this was not much help but i do sincerely hope this issue gets resolved soon!! i love using krita and it has been quite troublesome for me to keep reinstalling krita to get rid of the message, only for it to appear a week later.