NaNs in cofig file crash game when loading a vessel

[ihsoft]

At some point I noticed that switiching to some of my vessels results in a weird game behavior: from empty screen with a lot of errors in the debug log to a plain crash. After a long investigation I've figured out that it only happens to a vessel that has a "NaN" value saved into PersistentRotation_<username>.cfg.

Here is an example that results into a repeating error in the debug log:

MOMENTUM
{
    d199c734-cc47-4075-9e67-0ad0dfe7d1a1 = NaN,NaN,NaN
}
ROTATION
{
    d199c734-cc47-4075-9e67-0ad0dfe7d1a1 = NaN,NaN,NaN
}
DIRECTION
{
    d199c734-cc47-4075-9e67-0ad0dfe7d1a1 = NaN,NaN,NaN
}
REFERENCE
{
    d199c734-cc47-4075-9e67-0ad0dfe7d1a1 = Sun
}

This results in an empty screen and a lot of error in the log from MechJeb2 reported in each frame:

  getObtAtUT result is NaN! UT: <some increasing number>

This is not the only error, actually. There are more modules complaining but copying them all here doesn't seem to be a good idea.

I workaround it by periodic cleanup of the mentioned config file by just dropping records with NaNs but it would be nice to have a protection in the code to not write out NaN values. I cannot give repro steps to make PR writing these values.

A side note to this config file: looks like it stores info for objects that have PR setting set to NONE. Why? If not set, just skip it to avoid any issues.

[markusa380]

Will look into that.
Anyway, does it happen without any other mods installed? If not, please post the mods you are using.

[ihsoft]

Never tested it with no mods. This issue needs some time to accumulate. It happens from time to time on my old save game (~200 hours of game) but on the fresh start I never witnessed it. In the oldest save game PR tracks ~100 different GUIDs in the REFERENCE section.

From my personal observations I'd say this issue is somehow related to "revert flight" option and KAC plugin. When I frequently revert flights (e.g. while testing a new design) and switch between vessels via KAC the probability of getting the issue is gets much higher. Though, I cannot give exact reproduce steps.

[markusa380]

I was never able to reproduce the bug. Also, the new save system should have fixed that.