Presentation conversion causing component crash

[antobinary]

Describe the bug
On some systems (could not reproduce on docker-dev, only on droplet BBB server), specifically when maxNumPages property is overridden on /etc/bigbluebutton/bbb-web.properties let's say to 256 (default is 200) but not touching https://github.com/bigbluebutton/bigbluebutton/blob/v2.7.x-release/bigbluebutton-html5/private/config/settings.yml#L810...
When uploading the combination of three specific files ... (attached here)

chm_m9b_fin.pdf
chm_m9b_ex.pdf
chm_m9b.pdf

and uploading them specifically in batch (not one by one) we see several odd things happen.

1. always the presentation with name chm_m9b_fin.pdf gets marked as desired new current presentation. If I manually set the existing default.pdf to be current in the dialog, the bug does not happen.
2. The presentation area crashes with the following error
   

BBB version:
BigBlueButton 2.7.4