I created a new file in Bitbucket Cloud (using the web interface - bitbucket.org).
I followed the next steps:
and I got the following message:
We had trouble committing your changes.
How can I solve this?
It is a bitbucket bug.
It happens when you pasted a text using right click > Paste and no key was pressed when the cursor what inside the input box.
When you get the message:
We had trouble committing your changes.
you can see "Creating on branch" below (without the file name).
When it works fine, you will see the file name between "Creating" and "on branch".