I always play at 12 ups to keep the gpu from overheating, but the hand crafting speed gets to low because of that and the solution was always to go to map settings and click the checkbox for Adjust Hand Crafting Speeds, but that is not working anymore. In the previous version I had to uncheck it and check it again for it to work, but now it doesn't work at all.

This is new issue in version 1.6.4?

Also can you post a list of all the mods you are running? Another one may be changing hand crafting speeds after GTTS does.

I tested with no other mods, installing factorio from zero, but the problem still occurred. But then I installed the version 1.6.2 of GTTS and the problem still occurred the same way, and it didn't use to before, so maybe it's a problem with the new version of Factorio? I'm using version 1.1.59.

Did you by any chance enable the "Safe Mode" option in the mod settings?

Also can you try running these commands in the console and reporting the value?

/c game.player.print(game.player.character.character_crafting_speed_modifier)
/c game.player.print(game.player.force.manual_crafting_speed_modifier)

I didn't activate the safe mode.

/c game.player.print(game.player.character.character_crafting_speed_modifier)
Cannot execute command. Error: [string "game.player.print(game.player.character.chara.."]1: attempt to index field 'character' (a nil value)

/c game.player.print(game.player.force.manual_crafting_speed_modifier)
value: 0

I just created a few Freeplay games and there it works fine, as long as I disable Adjust Hand Crafting Speed and enable it again once after creating it. So it's only in Sandbox mode that it doesn't work at all.

You can use the command below to set the crafting speed then:

/c game.player.force.manual_crafting_speed_modifier = 4

I will consider adding an option to run that command automatically, but that is much more likely to interfere with hand crafting speed research mods.

All right. Thanks!