Code changes are done and tested the application. Working as expected, updated code is present at: https://bitbucket.org/jaya-sravani/integrated-genome-browser/branch/IGBF-3920. Please review and let me know if there are any issues. Below are the scenarios tested:

• IGB is not present for the genome and RefGene is present in the available tracks: RefGene gets loaded
  
• IGB is not present for the genome and RefGene is not present in the available tracks: RefSeq gets loaded and the data is loaded only if it's present for the first chromosome else empty track gets loaded
  

Here is the pull request: https://bitbucket.org/lorainelab/integrated-genome-browser/pull-requests/1040

Tested using Sravani's branch on Mac.

Built IGB successfully with tests.
Loaded the human hg38 genome (has IGB Quickload) UCSC REST did not load annotations (good).
Loaded the zebrafish sep 2014 genome (no IGB Quickload, has refGene and ncbiRefSeq UCSC REST tracks), refGene was loaded by default (good).
Loaded the human T2T genome (no IGB Quickload right now, has ncbiRefSeq UCSC REST track), ncbiRefSeq was loaded by default (good).
No errors in IGB log.

Ready for pull request.

PR: https://bitbucket.org/lorainelab/integrated-genome-browser/pull-requests/1040

PR is merged and new installers are built and deployed to bioviz.org early access section.
Ready for testing.

Tested on main branch installer, was able to see ncbiRefSeq or refGene load correctly from UCSC. No errors in log.

Closing ticket.