Help! Mod menu send chat messages in Photon games

[Duston]

Hello. I have been trying to send chat message in a photon game from calling needed methods, but every time I tried game crashed.

The method I used:

public void OnClick_SendFreeTextMessage()

It belongs to CanvasChatManager class. Previously I got inputfield of this class and set the text of the message. I got the instance from Awake() method of the same class.

void sendChatMessage(void* instchat)
if(instchat!=NULL)
{
void * tinputfield = *(void* *)((uint64_t) instchat + 0xB0);//the field of class with message text
*(monoString* *)((uint64_t) tinputfield + 0xD8) = String_CreateString(get_StringInstance, msgtext, 0, (int)strlen(msgtext));//new message text
OnClick_SendFreeTextMessage(instchat);
}
else LOGI("instance is null");
}

When I tried calling OnClick_SendFreeTextMessage() via button in mod menu game crashed.

But when I tried only to hook this method like this to change the message text before sending message the normal way by pressing send message button in game, everything worked fine.

void (*old_OnClick_SendFreeTextMessage)(void* instchat);
void OnClick_SendFreeTextMessage(void* instchat)
{
void * tinputfield = *(void* *)((uint64_t) instchat + 0xB0);//the field of class with message text
*(monoString* *)((uint64_t) tinputfield + 0xD8) = String_CreateString(get_StringInstance, msgtext, 0, (int)strlen(msgtext));//new message text
old_OnClick_SendFreeTextMessage(instchat);
}

I tried calling RPC method RPC_ShowMessage(string messageText), chat text appeared for a while (only for me, not the other players) then game crashed.

I'm still a beginner, if anyone knows what am I doing wrong / missing here your advice is appreciated.