Does decompressing upk hits gpu performance?

[spiritovod]

@Abuali: Decompressed packages can affect loading times and cause stutters if the game is running from low-speed hdd (for ssd it wouldn't really noticeable). But that's in case if all game will be decompressed, with a single decompressed package there is no difference. Can't tell about integrity of the package(s), since you didn't provide samples, but most confusing part in the error message is that it looks like running in 32-bit environment, while the game only supports 64-bit one. It would be better to submit an issue on the tool's github with samples and all.

[spiritovod]

@Abuali: Overall package format seems fine, as it can be read by umodel without issues. Most likely the problem is related to modded part, as modding tool is replacing references to existing objects with newly appended to the package. The issue can be caused by undefined behavior, when the game is trying to access replaced entries due to savedata parameters or particular game/system settings, like default language. The reason why it may crash on one system and may not on another is related to general memory handling and garbage in uninitialized pointers/values.

Another reason can be some edge case for unicode handling, for example adding character, which can't be processed properly with current locale settings on certain pc. Anyway, you can easily check if the issue is related to modded part by using decompressed unmodified package - if it works fine on target pc, then the issue is related to modding and should be addressed to the modding tool.