nucleo-L053R08: Flash programming stops at 93%.

Only a couple of days ago, I startet to work with STM32cubeIDE. I'm new with STM32 and also new with the cubeIDE, but I do need this in future for product development. I'm using a nucleo-L053R8 board.

After starting a very simple test script to let blink a LED, I downloaded this a few times onto the board, using F11(Debug), which worked fine a few times.

At any time, cubeIDE crashed an had to be killed by using task-manager. From that time, I'm stepping from one problem into the next, not being able to get anything work again.

Currently, the status bar stops at 93% when downloading the software:

Probably after some timeout I get the following error message:

Using google, did not show any usefull result to. There a lot of hits, but everything seems not to be applicable to my configuration.

Currently I'm realy frustrated with the IDE, as it is too complex for a beginner to understand where to start searching for a solution.

BTW: What I did so far: Uninstalling and reinstalling cubeIDE with no result. Starting a new project, which just resulted in differen error messages. Upgrading the ST-Link firmware on the board, with also no result.

Any idea, what I can do to get things work as intended?