Unit in spotting range not spotted. Bug?

[case23]

Playing Sealion '40 on FM, I moved a Pz-IVD to two hexes away from the airfield next to Bristol, confirmed that the airfield was unoccupied and then moved a second tank to capture it and sit next to Bristol.

Imagine my disappointment when the AT gun on the airfield appeared and ambushed my tank. Weather was cloudy/dry. It wasn't that I just didn't notice the unit, since it's not possible to be ambushed by a spotted unit.

Does spotting have a chance of failing? I've had this happen before and so I've gotten into the habit of pausing for a second or so after moving a unit to allow any spotted units to appear. Not long enough this time.

I immediately saved the game and then reloaded from start of Axis turn, but was unable to duplicate the problem in 7 or so attempts. Then I accidentally clicked start of the Allied turn and destroyed the Axis turn start saved state.

In the Norway scenario, I've often had delays of several seconds before ships within spotting range of my aircraft actually show up. It seems like there's a lag (during which the game is still active, units can be moved, etc.) before spotted units are placed on the map. This isn't a rain issue, since in that case the units would never show up.

It's almost like there's an async "spotting" thread that sometimes lags the program so that units occasionally don't show up for a while. Not suggesting that's the actual problem, of course, but that's the feel of it.

Bug? Feature? Have I entered a mystic dimension, not of time or space, but of mind?

- Case

[ThvN]

The only thing I noticed with spotting is that I need to deselect a unit after I have moved it to spot anything. So if I fly an aircraft somewhere and leave it selected it does not update the spotting, although the recon units seem not to be affected by this? But if I move a unit, and do not deselect it but immediately select a different one, it still updates the spotting quickly, so this is not the problem that you are describing I guess.

You are not playing with a mod or a modified equipment file, are you? Because this sounds as if the AT gun had the 'camo' trait.

[case23]

Nope, no mods. I did install the 1.13 patch immediately prior to playing this game, but this looked identical to the problem I've had in the Norway scenario with ships not showing up for aircraft for significant time (several seconds). I've gotten in the habit of moving a plane for spotting purposes and then moving some some other ground unit in order to give the game time to update spotting for the plane. Anyway, that was true well before the 1.13 patch. I think I may have also seen this with other ground units on one other occasion, but memory may be playing tricks on me there.

I also specifically confirmed that the hex was "illuminated", i.e. lighter in color to show that it was spotted before moving the second tank.

In case it's relevant, this is under Windows Vista, all current patches/updates installed. At work and not remembering whether it's 32-bit or 64-bit.

- Case

[Rudankort]

This is a very strange problem. Spotting works in a deterministic way, there is no background thread of something, and when the game must reveal the map, it just does that. As Thomas correctly stated, the game will not reveal the map while Undo Move is possible. But when a unit is deselected, or another one is selected etc., the move is "committed", undo is not longer possible and the map should be revealed instantly.

There are only a few units which are exceptions from general rules - these are submarines and minefields.

If your problem is not explained by the above, then I need more info on it - in which cases exactly does this happen, how to reproduce it?

[case23]

Yep, it's hard to fix a problem that isn't there (i.e. can't be reproduced). I'll keep an eye out and if it happens again see if I can find a reliable way to reproduce it.

- Case

[case23]

Just to log the info, it's 64-bit. Also, I have Undo turned off. If I discover anything more that's useful, I'll add it here.

[case23]

I've been able to duplicate similar behavior in the Norway scenario. Unzip and load attached saved game.

1. Attack the sub immediately to the west of Bergen with the Bf-110 already above it.
2. Fly the Bf-110 four hexes south and one hex southeast so that it sits on the peninsula between Stavanger and Bergen.
3. Unselect the Bf-110. Note the two spotted destroyers and heavy cruiser.
4. Select and unselect other units. Note that nothing strange happens.
5. Move some other unit or attack with it. Ships now appear in the spotting range of the Bf-110.

It looks like the ships appear immediately after the resolution of the action (attack or move), while whichever unit is acting is still selected.

Hope this helps.

- Case

[ThvN]

Good catch, I've been able to duplicate it with your savegame and instructions. Very odd indeed. I wonder if it caused because a submarine is involved?

EDIT: I just tried to get a similar situation in Sealion 40, and I can do so only with the 'Undo Move' option unchecked. And not just for a submarine/airplane combination, but for everything I tried: if an airplane attacks another airplane and moves off afterwards, the same spotting update bug occurs. So this looks more like a 'general' bug with the 'Undo Move' function?

[case23]

It seems likely it's related to having Undo unchecked. That's my default option, but I suspect most people probably leave it checked, which would explain why this hasn't been flagged previously.

[Rudankort]

Thanks Case, I'll check and fix this. Yes, most likely it is related to Undo unchecked in combination with some other condition (e. g. presence of submarines could be the reason).

[case23]

Looks like not subs -- just had this happen in Poland. (Well, unless there are some *very* sneaky Polish subs around )