This is a FAQ for the patches only.  There is a FAQ for the main mod on the main mod page.
Unless stated otherwise in the sticky, make sure your patches and the mods they patch are up-to-date before you post questions about them!

Why was support for X Y or Z mod removed?
We remove support for mods for a number of reasons; it may have been removed from Nexus (we don't support off site mods not hosted on Nexus), the quality may have gone in the toilet in a recent update, it may be no longer compatible in any way, the patch may be redundant after an update to the mod or Legacy, objectionable or lore/canon unfriendly content may have been discovered, or we just decided their space was better awarded to something else.

I installed this and now my save is corrupted/game is crashing/hanging at startup!
If you are running a lot of patches, it is highly recommended that you install Engine Fixes. By default Skyrim can only open 512 files at a time, this raises the limit quite a bit. Symptoms of this issue include the "False Save Corruption" bug and/or crashing.

If the game is still crashing or hanging at startup you may need to go into the .toml file included with Engine fixes and raise this limit again. I recommend "MaxStdio = 4096". This is located on line 11.

I'm a little confused as to which platforms you support.
Legacy is a huge, complex mod that is challenging enough to support as it is.  Therefore we only support Legacy installations on PC that use official content and that follow the guidelines in our documentation on the main Nexus page.  We do not support games on VR, Switch, or consoles.   There is a third party port for xbox, but all support for it is handled by the porter and not by the Legacy team.

I don’t see a patch I used to use in the list of available patches.
Several patches were discontinued and several were added with the transition to Legacy v5.  A list of changes and brief explanations can be found on the main mod page under articles.  The other possibility is that you are familiar with a legacy patch that is from the other mod author’s page; check there for updates.

I know there is a patch for a mod I want to use but your patch FOMOD doesn't have it.
The Legacy patch FOMOD contains the patches that the Legacy team officially supports.  Other patches written by third parties are maintained on their own pages; sometimes on the parent mod page, sometimes on a page all of their own.  Try first searching the other mod's page for the patch, or any notes about it in the comments.  A Nexus search may also be helpful.

But I can’t find a more recent patch at all!  Can’t I just use the old one?
By the Divines, no!  Do not use old patches that have not been updated to work with v5!  Since Legacy v5 was released December 16, 2019, if you have some sort of Legacy patch from before that date it is v4 and should not be used in a v5 game.

I have a supported mod installed but the FOMOD patcher is not selecting/detecting it.
First, check to make sure the mod is activated, not just installed, in your load order.  The FOMOD will only detect ESPs it finds active. Which leads to the second point, some items – like Ruins Clutter Improved – do not have ESPs, so they are not check-marked but also are not greyed out in the installer.  This means you can manually select them to install the patch.  Third, it's also worth noting that the FOMOD won't detect and install patches for mods in merges, nor will the patches work with the merge, even if you manually installed them.  Either don't merge those mods or create your own patches for the merge(s).

I added this/these mod(s) to my game already in progress.  Can I just rerun the FOMOD and have everything work right?
First of all, changing your load order in any way (adding/subtracting/reordering) after starting a game is not a good idea - unless you are totally fine with starting over if things go sideways.  As long as you have not re-sorted your load order and/or regenerated your bashed patch, it might work but it is a pretty unsound idea to have a mod and its patch(es) loading after the bashed patch.  Rerunning the FOMOD will indeed discover any new activated supported mods and add the patches.  However, in this case, it would be best to remove the added mod(s) and roll back to a save before you installed.  Save the new mods for the next time you start a completely new game.

Secondly, Legacy configures itself based on the mods it detects when you start a new game.  Sometimes content added later will work correctly (depending on what it is), but more often than not they will not correctly display, display rooms/spaces won't appear, MCM checklists will be incorrect (even after a rebuild), etc.  Again, it's better to just make a note of a mod you are interested in and install it for your next game.

And if you did re-sort your load order and/or regenerated your bashed patch after installing, time to start a new game.

I see that you guys don’t support Legacy on NMM.  What’s the deal?
NMM was a good mod manager back in the day, but time has passed it by.  The Nexus discontinued support for it in December 2016.  Frankly there really isn’t a compelling reason to stay on NMM versus MO2 or Vortex.  Along those lines, none of the Legacy team uses anything other than Vortex or MO2 and thus won’t entertain questions from people using NMM (even the community version) about any issues in your game. 

I'm using a guide/modpack and I have questions/problems...
Then you will have to take any game issues up with the maker(s) of the guide.  The Legacy team doesn't at all dislike the guides themselves or the folks who use them, it's simply that such setups add a layer (or more) of complexity beyond supporting Legacy and it's patches, which is challenging enough already.  Also the folks involved with any given guide understand their configurations far better than the Legacy team ever could, so when issues surface (whether you believe them to be Legacy-related or not) please take them up with them.

I am using a translated version of Legacy of the Dragonborn and/or the patches.
Since the various translations of Legacy or the official patches are beyond the team's control (we don't know what they changed since we can't read it), we will be of very limited help to resolve issues. Please make sure to begin any requests for help by letting people know you are using a translation. You should also contact the team that performed your translation, since they may be of more assistance.

Why are there no CC patches here?
The Legacy team, for the most part, doesn’t use the content and are philosophically opposed to how the CC came about and was handled.  There is a Legacy page for CC patches, but they are offered there “as is” by third party authors and are not supported by the Legacy team.  Note: this includes the free CC content that came with the SSE 1.6.X upgrade.

Can you merge Legacy’s patches?
While technically possible, merging of the Legacy patches is not supported by the Legacy team.  The patches provided are ESL-flagged ESPs and do not count toward your regular plugin limit, so there is no reason to merge them except for maybe the smashed patch.  But since RAB Smash Splitter works around smashing load orders larger than 254, even that's not really an issue.  It’s worth noting that should you update a patch and then redo a merge you will re-roll the FormIDs, thus mucking up your save.  Just say no to merging Legacy patches! 

But I need to merge patches because I use VR and I’m limited on slots!
Thus the "technically possible" part; you can do it, but for reasons listed in the bullet above – and the fact that none of the team has VR (and therefore we don't support VR) – we don’t support games where you’ve done that.  It may work perfectly fine, but you are on your own.

I have items on display in the museum that I have not found yet!  What’s going on?
This happens if you have merged your patches, started playing, and then re-merged the patches due to additions, subtractions or updates.  And then used that new merge on your game in progress.  We told you this was a bad idea!  Time for a new game. 

I’d like to request a patch for a mod with Legacy.
If it’s a conflict resolution patch for a popular mod, the answer is maybe – depending on time and interest.  Otherwise perhaps the other mod author would be interested in creating it.  However, if it’s for adding displays to the museum, the Legacy team is not taking any more requests to add content.  Instead there is a process linked on the description page for allowing interested third parties to apply for space in the museum. Note this doesn’t mean it will be approved, and the third party will have to build and maintain the patch, but there is a process available. 

But what about patch(es) for Beyond Skyrim, which is really popular!
Beyond Skyrim is a really great project, and Beyond Skyrim Bruma will only conflict in minor ways with Legacy; you can play both with no real issues.  The problem is mostly in planning for the future.  First is that while Beyond Skyrim Bruma may not conflict with Odyssey Act 1, the future acts of Odyssey will overlap with other part of Beyond Skyrim - so you'd wind up with two different instances of multiple locations which would ruin immersion.  The second issue is planning for how much content the aging Skyrim engine can handle before it waves the white flag.  Legacy right now is bigger than all 3 Official Expansion DLCs combined, and Beyond Skyrim is as well.  Odyssey Act 1 will almost certainly wind up being bigger than both Legacy of The Dragonborn and Beyond Skyrim - Bruma put together - and there are other areas of Beyond Skyrim coming online as well as 7 more planned acts of Odyssey.  You can see where this is going. 

For those reasons, the team realized that instead of supporting Beyond Skyrim Bruma, and then turning around and cutting support for the other Beyond Skyrim areas, it would be better to manage expectations up front. So the decision was made to step away from it now and encourage people to do separate games for either project.

What about some of the popular unauthorized ports of LE mods?
We can't and won't support non-official ports of LE mods (or straight LE mods at all, for that matter), which of course includes self-ports.  They may or may not work with Legacy, so you are on your own for doing any conflict resolution patches.

I notice there are some unique items from a supported/patched mod that don't appear to have displays in the museum.
This is occasionally an oversight but most often intentional.  The rule of thumb for displays is it's not enough just to have a unique name, the model for the item must also be unique.  If Fred's Awesome Plate is just plain steel plate armor, it's not getting a display.  Also, although there is room for some things, adding more content from a mod also depends on the kind.  For instance, finding space for a unique ring might happen, but adding new sets of armor is highly unlikely for lack of suitable space.

I have a full load order and all the Legacy patches loaded and activated, but I still have problems.  For instance, I can’t place this thingamajig in the museum, what gives?
Legacy’s patches are built with only the mod in question and Legacy to get a clean patch without other mods interfering.  In this example, there may be 2 or more mods adding items named “thingamajig” (with different FormIDs) that have Legacy patches to add content to the museum.  But only one patch (the last one) in your load order will win the conflict. 

So can’t you create combination patches?
Technically yes, but in reality with updates from other mod authors, this becomes waaay too much work and extremely unmanageable really quickly. For example, if you have 3 mods affecting "thingamajig", based on user preference, there are 7 possible combinations of installed mods, which means potentially 7 patches.  If 1 of the 3 mods updates, 3 combo patches would have to as well. No Bueno!

So what do I do to resolve that problem?
Since everyone’s load order is unique, there really isn’t a cookie cutter type answer.  You are going to have to decide whether you are willing to put up with the problem(s) you have found, or you are going to have to create your own conflict resolution patch(es) in SSEEdit (xEdit).  Note that this also may require editing your bashed patch.

After updating my patches, my Legacy MCM Checklists are all out of whack.
Go to the Legacy Settings MCM, scroll to the bottom and select the option to rebuild checklists.  Wait several minutes for it to complete.  If that still doesn’t work, open the console and type:
Setstage SKI_ConfigManagerInstance 1
Again, wait several minutes for it to complete.

When I get to the museum, the entrance is messed up.  Trees in the doorway, rock wall in the doorway, door won’t open, no doorway.
You have a conflict with another mod or patch, or you have not activated your installed patches.   Conflicts can include: mods that are incompatible with Legacy regardless of whether a patch is made or not, mods that require a patch but don’t have one, out of date mods, out of date patches, or missing conflict resolution between patches.  

Check that you have the most recent Legacy-supported patches and check for v5 compatible patches on the mod author's page.  In the event that Legacy has an official v5 patch and a third party mod page also has one, install the Legacy one only.  Start a new game after making any changes.

I can’t seem to get BadGremlins collection to properly work.
Make sure you are using the “Merged All 4 BSA” version and not the individual versions of BadGremlin’s mods.

I am running Dawn of Skyrim and JKs Skyrim and can't seem to get them patched for Legacy correctly.
First make sure you are running the most recent versions of both mods, particularly since Dawn of Skyrim changed the name of the esp not long ago. Next you need to install the mod that patches those two mods: JK's Skyrim - Dawn of Skyrim - Patch.  Legacy has a patch for that mod in the installer. So install and activate Dawn of Skyrim, JK's Skyrim, JK's Skyrim - Dawn of Skyrim - Patch, and then run the Legacy patch FOMOD to install the correct patch.

I'm running Wintersun but don't see the shrines for Auriel or Nocturnal in the Wintersun display, even though I visited them.
Since those quests are vanilla content (Dawnguard and Thieves Guild) and not added by Wintersun, they are in other locations in the museum.

The patcher installed the patch for MorrowLoot Special Edition and I use MorrowLoot Lite.
The name for the ESP for both mods is morrowloot.esp, so the FOMOD will install the MorrowLoot Special Edition patch if it finds that ESP - regardless of which mod it came from.  Morrowloot Ultimate does not have this problem as the ESP has a different name.  If you are using Morrowloot Lite you will need to find and delete/disable the patch.  Then create a conflict resolution patch as needed.

For issues from versions of Legacy patches older than the current ones, and related upgrade issues, there is a Patches FAQ archive here provided as a convenience.