Crash when tabbing out of various fields in Parameter node

[MicroTransactionsMatterToo]

Material Maker version:
v1.3-1

OS/device including version:
Linux version 6.8.9-hardened1-1-hardened (linux-hardened@archlinux) (gcc (GCC) 13.2.1 20240417, GNU ld (GNU Binutils) 2.42.0) #1 SMP PREEMPT_DYNAMIC Thu, 02 May 2024 21:41:31 +0000

Issue description:
When editing a group's parameters (or any other node that shares it appearance and functionality i.e. Remote), tabbing out of the first or second dialogues, then attempting to edit them again will crash Material Maker. I'm not sure if this occurs with other fields in the node.

Steps to reproduce:

1. Create a new material
2. Create a remote node
3. Create a linked parameter
4. Edit the first field of the new parameter
5. Press tab to finish edit
6. Attempt to edit the first field again
7. Crashes

Associated Console Output:

Godot Engine v3.5.2.stable.custom_build.170ba337a - https://godotengine.org
WARNING: XOpenIM failed
     at: initialize (platform/x11/os_x11.cpp:213)
WARNING: XCreateIC couldn't create xic
     at: initialize (platform/x11/os_x11.cpp:510)
OpenGL ES 3.0 Renderer: NVIDIA GeForce GTX 1060 6GB/PCIe/SSE2
Async. shader compilation: OFF
 
Cannot open user://export_targets
Failed to open user://library/user.json
Failed to open user://library/user_brushes.json
WARNING: Ignoring unsupported header information in HDR: GAMMA=1.
     at: load_image (modules/hdr/image_loader_hdr.cpp:50)
WARNING: Ignoring unsupported header information in HDR: PRIMARIES=0 0 0 0 0 0 0 0.
     at: load_image (modules/hdr/image_loader_hdr.cpp:50)
2
ERROR: Index p_index = -1 is out of bounds (data.children.size() = 2).
   at: get_child (scene/main/node.cpp:1362)
ERROR: Index p_idx = -1 is out of bounds (items.size() = 8).
   at: set_item_disabled (scene/gui/popup_menu.cpp:871)
Buffer histogram_5726 (updating) should not be invalidated status
ERROR: Condition "!is_inside_tree()" is true.
   at: release_focus (scene/gui/control.cpp:2030)
ERROR: Condition "!is_inside_tree()" is true. Returned: false
   at: can_process (scene/main/node.cpp:817)