Document Viewer can't be opened, NPE

steps to reproduce
1. login
2. open document viewer
3. try open attachement

**see screencast**

![0ywtx8R08M](https://github.com/logilite/logilite-DMS/assets/3862461/af9a8e9c-36ea-47da-8d57-9c564e3d8085)


**the log**
<img width="1434" alt="Screenshot 2023-12-05 at 22 34 32" src="https://github.com/logilite/logilite-DMS/assets/3862461/9139dc12-89aa-4bc8-9358-c639bd1cd4ce">
