Welcome @naila2025
First, please try again. This sort of error with the pop-up should be very rare.
Then if this is still happening, we can help to determine what the problem is if you share back the history. You can also add in some screenshots if this is happening when you are submitting the job.
As an extra, I started up the workflow associated with the tutorial at UseGalaxy.org (is this where you are also working?). This should capture any technical problems on the server or with this tool specifically.
- Tutorial → Hands-on: Exome sequencing data analysis for diagnosing a genetic disease / Exome sequencing data analysis for diagnosing a genetic disease / Variant Analysis
- Workflow Invocation (with linked workflow and history both in a shared state) → https://usegalaxy.org/workflows/invocations/d9b8632ec9e7da78
How to share back is in the banner of this forum. You can post the history share link back here, then unshare once we are done. 