Environment and versions:    Operating System:        Name: Linux        Version: 3.10.0-1127.19.1.el7.x86_64        Architecture: amd64    Java:        Version: 11.0.8        Vendor: AdoptOpenJDK        Home: /root/klaros-testmanagement/jre        Runtime Name: OpenJDK Runtime Environment        Runtime Version: 11.0.8+10        VM Name: OpenJDK 64-Bit Server VM        VM Version: 11.0.8+10    Database:        Name: PostgreSQL        Version: 12.4        Driver Name: PostgreSQL JDBC Driver        Driver Version: 42.2.16    Version:        Installed Version: 5.0.3 - Build 4876 (2020-10-14 19:46:29)        Release Date: 10/14/2020        Latest available Version: ""        Home: /data/klaros-home/    License: Community Edition    Installed via: https://github.com/klaros-testmanagement/klaros-docker/blob/master/Documentation.adoc


StepsToReproduce: 
- Navigate to "Evaluate"->"TestCaseResults"
- Click on filter button
- Setup filters:
    - Field = "Test Suite"
    - Type = "Equals"
    - Value = "TestSuiteName"
- Click on "Apply" button
- Click on "Export table" button
- Choose "PDF Export"

**BUG:**
"Well, this is unexpected ..." page shows up.
**Exception line:**
`The number of columns in PdfPTable constructor must be greater than zero.`

P.S.: Is there ability on your forum to attach files? I have additional, may be, useful files to help analyze problem (screenshots, video/screencast, logs)