Hello,
Well, I found the source of the error, finally it was not your file which was corrupted but the API of access to it. I wanted to anticipate the evolution of this API by using the last available version without realizing that it was not finalized. So we have to go back to the last stable version. The incriminated file is the h2-1.4.200.jar located in the "lib" sub-folder of your installation. There are two methods to make the modification.
a) manual method :
1- download the h2-1.4.199.jar file from the following address https://framagit.org/ostorybook/mainApp/-/raw/master/lib/h2-1.4.199.jar
2- locate the oStorybook installation folder and the subfolder "lib" and save the downloaded file there
3- delete the file h2-1.4.200.jar from the subfolder "lib".
Depending on your operating system (Windows, Linux or MacOS) you will have to perform these operations with administrator rights.
b) "automatic" method ( more simple)
1- remove the installation of oStorybook
2- download the version under development at the following address
http://download.tuxfamily.org/ostorybook/next/
(take the file that corresponds to your system)
3- install oStorybook
Sorry for the disturbance.
Translated with www.DeepL.com/Translator (free version)