GTR2 not reading or generating weather.txt

I have been modifying the weather.txt files successfully but now GTR2 seems to stop interacting with it. I am not sure what is going on with it.

So this is my understanding of how it works. In the main GTR2 folder there is a folder named UserData, which contains a folder named Log. In there is the weather.txt file. GTR2 generates a new weather.txt for each race, wiping any changes you make. It will create a new weather.txt files if you delete it. However, if you put it to read only then GTR2 will use the information in the existing weather.txt files, meaning you can set minute by minute the weather (or use a program like AutoSimWeather to generate a new weather.txt). I believe that you need put the race conditions to be Changable and do not turn on Time Scaled Weather for this to work.

As thing stand, GTR2 seems to be ignoring it. Any weather.txt I put in the Log folder makes no difference to the weather in the race. Additionally, I can turn off 'read only' on the weather.txt file and it does not generate a new one, and even delete the file and GRT2 does not generate a new one. I have tried doing races with Changeable weather and without, and with Time Scaled Weather and without, and the result is no different.

Any idea what is going on? I cannot think why this is relevant but this seemed to occur after doing a 24 hour race for the first time, so I am wondering if that did something.

Are you sure that the sessions lengths are perfectly the same in the weather file compared to the ones really in use for this particular track ? ... including practice(s) and qualification(s).
If it's not the case .... it will not work for the race.

Same if you shorten a session without using the time acceleration button in game.

EDIT: have a look in the .gdb file of the track you're using as the problem is mainly this line for some tracks:
QualifyDuration = xxx

You have to respect this duration in your weather file or modify this line in the gdb file of the track as both durations need to be the same.

Try to edit your weather.txt file and later save it with 'Read-Only' attribute. It always works for me.

Thanks for the advise, it has helped me understand the file structure of GTR2.

However, I could not get the proposed solution to work. I tried to align Qualify1Duration, Practice1Duration, Qualify2Duration, Practice2Duration and also RaceTime with the length of time in the weather.txt files but to no avail. A clean install of GTR2 seems to have solved the problem. I'll let people know if it occurs again and I find a solution.