Description:
I've been experiencing various lock ups after creating and editing forms when I exit the program and I click "save".

I've found I've been able to cause this to occur 100% of the time when I add a folder, don't save, and tell it to save on exit.

The lock ups have occurred on me when without adding a folder, not sure what else triggers it, other than pure data entry doesn't seem to cause it.

Occurred for me on both windows and linux using new databases.  

Steps to Reproduce:
1. Use database using embedded.
2. Go to forms.
3. Add folder.
4. Click to exit program.
5. Click yes on "Save Changes to.." Dialog.


Actual Results:  
Program locks up.  Have to End process to kill it.

Expected Results:
Close normally.


Reproducible: Always


User Profile Reset: Yes



Additional Info:
Linux Laptop
Version: 5.4.2.2
Build ID: 1:5.4.2-0ubuntu0.17.10.1
CPU threads: 2; OS: Linux 4.13; UI render: default; VCL: gtk2; 
Locale: en-US (en_US.UTF-8); Calc: group

Windows Computer:
Version: 5.4.5.1 (x64)
Build ID: 79c9829dd5d8054ec39a82dc51cd9eff340dbee8
CPU threads: 8; OS: Windows 6.1; UI render: GL; 
Locale: en-US (en_US); Calc: group


User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0