Have you followed the basic troubleshooting procedures? Debug on, no Downloads folder, etc.? Because as you described your problem could be pretty much anything.
If you didn't, do that now, then post the error log(s), so someone can try to help.

I had the very same issue, but apparently it solved patching the game.

First, thank you again, Inge for your work: very much appreciated

Second, I've updated with a small fix: package addeeded to first post.

Third, that lich is REALLY scary 

I think I have the same problem the OP has: in apartments, once a neighbor becomes invisible because it entered its home, it will not return visible when goes to work or exits its apartment for any reason: simply it remains invisibile forever.
I have to constantly click on the "fix invisible neighbors" of the lot debugger if I don't want my playables interact with ghosts and spirits only. I didn't a binary search, 'cause I haven't played apartments a lot, but if I find the culprit I'll post.

You're correct about the skills: they've maxed out the skills pertaining their assigned hobby (e.g. mechanical for Tinkering), but enthusiasm and OTH apparently not; I've just checked the Gaming hobby maven (freshly generated, and she has 0 enthusiasm in gaming, the gaming membership card and OTH = arts and crafts.
I guess it's because the OTH it's automatically chosen according to personality, and they wouldn't bother to alter the basic sim generator to take in account personality boundings for hobbies.

The only difference I spotted so far, it's that they belong to the 0x7FE4 family and they have the membership card (and quite often they don't even have any enthusiasm in that hobby nor it's their OTH), so, yes, you're right.
The same way EAxis programmers did with tourists, locals, garden club members and social groups; clearly not the smartest way, but here you are.

As far as I'm concerned, a site like that already exists, and from the very beginning: it's the Exchange  .

Uh, Isn't it that way by design? I remember they always acted that way, since the base game.

Wha...? I was always sure I'm a Baby Boomer, now I discover I'm a Generation X instead  .

Witch, that picture is priceless.

(sorry, It was a temptation I couldn't resist)

Whatever is the thing that triggered your error, it's not because of debug mode ("boolprop cheat") active: debug mode only informs you that an error exists and tells you also what it is. So, your error still exists, only, you are not aware of what is happening behind.

Boolprop, in any case, is not a cheat.

The OP, indeed, asked about what problem could have triggered the error, not about the annoyance of the error window.

Hold on... deleting a sim who has family bindings wasn't a bad thing?
Is it correct deleting first family ties in SimPE and only then perform the bogaloo?

Dang! That's true, I always forget one can save the game in business lots.

You can't visit a home business with other sims: your issue depends on the zoning of the lot, not the type of sims.

Community business lots are normally visitable by your current playing family, business owner and employees will act pretty much like NPCs.

Actually, that error could be pretty much anything.

Please, follow these guidelines in FAQs on how to ask for help.

I call The Usual Eaxis Code Borkiness. The game is designed to wipe that stuff on purpose, in SS event.

Funny that I'm still trying to make a hack which does not process orphans and does not insert adoptees in family tree (a bare move in, that is). Probably I should simply let the game run vanilla, and voilà my hack 

When the Social Worker takes kids away, processes them so all their memories, wants history and family boundings are wiped out: they become clean like they were taken directly from CAS.

My very same thought.

The first time I saw an apartment sim putting down the bills near the mailbox I cheered: YAY! Eaxis did something right (i.e. LOGICAL), for once!
Of course, I was wrong.

Who, in the whole Universe, ever complained for that "bug" Rod Humble maybe?

Did you notice that the Rod Humble unique sim is hidden and protected from any "use" way more than any other similar sim? Pollination Tech is almost playable, in comparison.
I smell FEAR...

*Marhis runs to find a way to marry Rod Humble to Bigfoot*

I want the penguin marry Bigfoot.

Great, I've found it, at last on the Mac. I'm almost sure it installed with Spore demo.
It's concealed in a system plist (you need a plist editor to check), hidden as well (it's a dot-something). In mine it's .GlobalPreferences.plist, in /Users/<yourloginname>/Library/Preferences.  This plist stores some Finder prefs, like iTools username, # of recent documents to list, and so on.

Proof:


Now: does somebody know what do I need to do? Deleting those entries in plist is enough or have I to perform additional stuff?

They do. I had a sim demoted just because he kicked the shit out of one of them twice.
Losers

boolProp testingCheatsEnabled true
boolProp allow45DegreeAngleOfRotation true
boolprop ShowLotPackageFilename true
boolProp petActionCancel true
boolProp ControlPets on
intProp maxNumOfVisitingSims 50
floatProp tvVolume 0.2
uintProp maxTotalSims 50
uintProp maxTotalHumans 40
uintProp maxTotalPets 10
boolProp enableOceanReflection true
boolprop ShowCatalogePFlags true


#--------------------------------------------------------------------------------------------
#     alias         real command                                    brief help                         full help
#     ------------- ----------------------------------------------- ---------------------------------- --------------------------------
alias exit          hide                                            "Hide the cheat console window"    "Hide the cheat console window"
alias x             expand                                          "*Expand the cheat console window" "Hide the cheat console window"
alias h             help                                            "*Show the cheat help"             "Show the cheat help"
alias ?             help                                            "*Show the cheat help"             "Show the cheat help"

alias mvon          "moveObjects on"                                "Move Objects On"                  "Move Objects On"
alias mvoff         "moveObjects off"                               "Move Objects Off"                 "Move Objects Off"
alias flooroff      "boolProp constrainFloorElevation false"        "Constrain Floor Elevation FALSE"  "Constrain Floor Elevation False"
alias flooron       "boolProp constrainFloorElevation true"         "Constrain Floor Elevation TRUE"   "Constrain Floor Elevation True"
alias snapon        "boolProp snapObjectsToGrid true"               "snapObjectsToGrid TRUE"           "snapObjectsToGrid True"
alias snapoff       "boolProp snapObjectsToGrid false"              "snapObjectsToGrid FALSE"          "snapObjectsToGrid False"
alias iroof         "individualRoofSlopeAngle"                      "individualRoofSlopeAngle [15-75] - ctrl+alt" "individualRoofSlopeAngle [15-75]"
alias roof          "roofSlopeAngle"                                "RoofSlopeAngle [15-75]"           "RoofSlopeAngle [15-75]"
alias dormon        "boolProp dormSpecificToolsDisabled true"       "dormSpecificToolsDisabled TRUE"   "dormSpecificToolsDisabled True"
alias dormoff       "boolProp dormSpecificToolsDisabled false"      "dormSpecificToolsDisabled FALSE"  "dormSpecificToolsDisabled False"
alias edgeson       "boolProp lockTiles true"                       "LockTiles TRUE"                   "LockTiles True"
alias edgesoff      "boolProp lockTiles false"                      "LockTiles FALSE"                  "LockTiles False"
alias fam           "familyFunds"                                   "familyFunds [familyname] [amount]"     ""

alias aptbbon       "apartmentBuildBuyRestrictions on"              "apartmentBuildBuyRestrictions on" "blocco Buy&Build in appt. attivo"
alias aptbboff      "apartmentBuildBuyRestrictions off"             "apartmentBuildBuyRestrictions off" "sblocca Buy&Build in appt."
alias apton         "boolProp aptBaseSpecificToolsDisabled true"    "disables build/buy mode tools on an apartment lot" ""
alias aptoff        "boolProp aptBaseSpecificToolsDisabled false"   "enables build/buy mode tools on an apartment lot" ""
alias aptsuboff     "boolProp aptSublotSpecificToolsDisabled false" "enables build/buy mode tools in an apartment room (can give problems when used outside room)" ""
alias aptsubon      "boolProp aptSublotSpecificToolsDisabled true"  "disables build/buy mode tools in an apartment room" ""

#
alias zdorm         "changeLotZoning dorm"                          "Changes lot zoning to dorm"       ""
alias zgreek        "changeLotZoning greek"                         "Changes lot zoning to greek"      ""
alias zss           "changeLotZoning secretsociety "                "Changes lot zoning to secret society " ""
alias zcomm         "changeLotZoning community"                     "Changes lot zoning to community"       ""
alias zres          "changeLotZoning residential"                   "Changes lot zoning to residential"     ""
alias zhotel        "changeLotZoning hotel"                         "Changes lot zoning to hotel"           ""
alias zapt          "changeLotZoning apartmentbase"                 "Changes lot zoning to apartment"       ""
alias zwitch        "changeLotZoning secretwitchlot"                "Changes lot zoning to secret witch lot"       ""

According to EAxis specification, you'll have familiars only if Pets is installed, otherwise no familiars at all. So, no issues, apart of the usual EAxis' potential borkitude, I mean.

Heh, it did not occurred to me to take pics, I was too busy EWWW-ing to think, I guess. That damn outfit is flagged for every bloody category, too. There's always some ugly townie/NPC that suddenly shows up wearing it during weddings, or at gym, etc; just when you thought you had eventually changed all their damn outfits for every frikkin' category in their family bin.
Its wide distribution also appears to favour elder hags, apparently. And with the most ugly hair. And with Caus archetype face. I bet they also stink permanently, just because, by design.

The one and ONLY scenario that never happened in my game is that some playable would took home from work an Ecological Guru townie properly dressed. No way.
I'm sure it's sim gods who are punishing me for all the nasty things I made to their little thingies during the years.

That's the Natural whathever top career outfit; it should appear in the clothes bin also, I think with some unlocker mod for Uni outfits (windkeeper's maybe). That should explain why sometimes it is choosen in automatic family clothes bin for townies, graduated YAs and (as outerwear) pre-seasons sims.
I have it happen all the time; Goopy in fig-leaf building snowmen is one of my worst recurring nightmares.