Issues with Mounted weapons in single player maps.

[lss4]

I'm not sure what might be causing the issue (OldSkool 240, or the 469 patch), but after playing some single player maps I noticed that in some cases, if I ever use a mounted weapon in a map, save games will not work from that point on and trying to load will fail with an error message like this:

Failed launching URL.
Cannot find Font in file in Font Editor.DynamicFont2

Normally if I reload a game before I hit the bug I can still make working save games that can be loaded later on, but in rare cases, all save games on any map and any time (be it before or after using a mounted weapon) would cease to work until I restart UT.

-- Mod-specific details (SPOILER ALERT) --

I just started playing Xidia Gold and find myself having trouble saving/loading on the third map.

When trying to load the saved game (quicksave or not) it may fail with an error message. Originally I thought it was the known bug that has been patched, but after applying the fix the issue still persists. As far as I could tell, save games on that map appeared to work fine even without the official patch.

Eventually I narrowed down the cause. If I use the mounted machine gun during the phase when I have to hold the position for a few minutes fending off a number of Skaarj enemies before the door could be opened, from that point on save game will no longer work, showing that error message. If I do so without using that mounted gun, then save/load will still work for the rest of the map.

Should note that Xidia Gold is not the only one having the issue. Previously I tried a custom map named Enslaved and the save game was also broken at a later point. That map also had a mounted gun somewhere that I needed to use to fend off some enemies, and the breakage happened after that point. I did not really pay attention to the error message back then, until I encountered this bug in Xidia Gold. The issue in both cases was probably similar.

EDIT: Just tried Enslaved again. It seems I have a high chance to reproduce this bug if I save the game while controlling the mounted Stinger, but I did not hit the bug when I saved the game after I first used the mounted weapon then left. The error message is indeed the same one I got in Xidia Gold (above, outside the spoiler).

But not all mods are bugged. In Operation Na Pali there's a level where you could control a cannon to take out a very large amount of Skaarj enemies in front of you, and I did not recall encountering the bug after using the cannon... As far as I could remember, I never really encountered any save/load issue in ONP at all.

EDIT 2: This issue can be gameplay-breaking for the map "Na Pali Haven: Redux". It has many mounted guns throughout the map, coupled with waves of enemy spawns so on harder difficulties they're going to be used a lot, making this issue very trivially reproducible there.

EDIT: Some additions and corrections.