Mac OS load files browser bottom widget sometimes does not display correctly

[maxieds]

Demonstration of the problem (active bug)

This error has been noticed on multiple Mac machine installs, but we have so far yet to be able to reproduce the bug exactly. After using RNAStructViz for a while, sometimes, when clicking on "Load Files" to open more structures, the bottom widget fails to display correctly. As in:

The correct display actually looks like the following:

Suggestions of causes for the display issue:

• Loading and processing plots with the StatsWindow, followed by trying to open the Load Files dialog after closing that window?
• The following message gets printed to the terminal / console when the error occurs:

  Fl_Text_Buffer::remove_modify_callback(): Can't find modify CB to remove
  Fl_Text_Buffer::remove_predelete_callback(): Can't find pre-delete CB to remove

  Any users that are able to accurately, i.e., predictably with steps, regenerate this issue with RNAStructViz, please follow up below and let me know so I can figure out a fix for the problem!

Proposed solutions in the meantime:

In the meantime, whenever this happens, please just restart RNAStructViz again, or choose new structures to load without using the bottom widget in the dialog (less optimal solution).

[maxieds]

@ceheitsch I believe that the issue has now been fixed after some good discussions on sources of the original error with the core FLTK developers today. Please upgrade to v2.3.4-testing to see the changes.

[ceheitsch]

It's hard to verify the bug fix since we could never reliably reproduce it. However, I've been working with RNAStructViz a lot recently, and not experienced this bug so will go ahead and close the issue.