Today I could not copy a project and there was a problem uploading assets (maximum asset size exceeded.
Solved: Copy project copied several times. But I could not see it. Then there were 10 copies.
I deleted them and things worked again.
But this error of me brings me to a question:
How many project can we create and is the space for assets limited?
There is no limit… so you can Thunk all you want 
Yes, The maximum total size for assets is 10 mb. if you need more space, then a cloud server like firebase, could help here 
-Philip
Glad to hear your problem is solved
In Thunkable ✕, the maximum space for assets is 50MB per app.
https://docs.thunkable.com/thunkable-cross-platform/2-create/app-limits
oh, i didnt realise he was talking about Thunkable X 
…this is the thunkable x forum…
Thank you to all these helpful people in this forum!
I think my other problem was the account size limit of 200MB, because I used images of my iphone foto library in original size… and too many copies to test changes in my projects.