Constant blueprint corruption

I’ve written a bunch of blueprint code, but now I’m getting lots of blueprint corruption that is unfixable. Node connections are disconnecting everytime I open my project even if I fix them and save them, building an exe results in errors.

Is there a way of completely rebuilding my blueprint files? I think there is built up garbage in my blueprints that is confusing UE4.

One problem I’m currently stuck on. I want to add a new variable to a structure. If I do that, my blueprints get corrupted and I have to revert all my changes.

Any tricks to clearing this up? I’ve tried “Fix Redirectors in folder” That doesn’t help.

-you could use an old backup/autosave file -> just copy it into your content folder
-make sure to report this on answerhub -> https://answers.unrealengine/index.html
-which engine version are you using? :slight_smile:

Can’t modify blueprints without corrupting them

Currently my blueprints seem to work, but if I make certain modifications, I get total corruption and I have to revert using git. So, I really can’t continue working on my project at the moment unless the bugs are fixed or unless I can somehow rebuild all my blueprints so they don’t contain corrupted data.

This has been happening for months and I’ve been able to get past it by opening and resaving files, but now I’m stuck.

Blueprints are unreliable and unusable in their current state if data is being corrupted. If someone at Epic wants to get my code and fix my files, I can get them access on github. My blueprints are simple and I’m doing nothing weird.

I’m using 4.8.3 currently since 4.9.1 has fundamental blueprint bugs that make it unusable.

4.9.1 fixes corruption issues

I updated to 4.9.1 and I’m no longer getting corruption, so I think I’m OK.

Nevermind, 4.9.1 didn’t fix it.

After modifying some more stuff, The corruption came back. 4.9.1 still corrupts files.

OK, maybe I’m good

OK, I finally got it going. I had to reopen an interface file, add stuff, delete stuff, resave and reconnect all the broken connections and this time it worked. Tip: Open files, modify, save, undo modify, resave and that gets things back to normal.

Hey, I’m getting a similar issue - i’ve been getting around startup issues after adding variables to in-use structs by just reopening the project one or two times, but after adding another its permanently crashing on startup. What do you mean by an ‘interface’ file? Can you give more details on what you did to get things working again?

For anyone coming across this thread in the future:

-In each struct I added a bool, and saved each struct straight away
-Pressed play to get everything to compile
-Used ctrl+S to save all modified blueprints that were using the structs
-Closed and reopened the project
-Repeated the above process but this time removed the variable instead of adding it

No more startup crashes (for now). The one remaining issue of crashes and pin-links breaking after adding a reference in a struct to a blueprint i’ve created appears to be caused by a bug or something else.

Hope this helps someone.

That is typical memory leak thing, i had same stuff going on in 4.7.

what it does really: it overwrites next actor allocated memory and corrupts it. Sometimes actor that crashes everything is not one that corrupts memory.

best solution for this is to make backups every few hours (and keep old backups), then you can trace back which version of project was first to have memory leak, this is easiest way to find culprit. Then you can either delete that blueprint, or migrate healthy ones over.

They (epic) fixed a lot of those tiny memory leaks since 4.7 , but it still happens. And mine also happened after struct and enum use. So I think best way (for now) is to limit structs to only what is really needed. There is another possibility, but i am guessing now, that editing struct after it in use in several blueprints somehow corrupts its data.

there are a lot of issues with structs, typical one involve data tables and make all previous “break row” nodes corrupted on project reload.

I’m getting similar trouble and this time in doing a interactive dialog system and finding several issues are going on with the data tables. The Data Table does not like piping in the Delay Values into the Timer Function Node through the delay pin, Once the data pointers to the array struct become corrupted, It causes the data table to jump into the wrong row number location. So it may be reading from row 1000 but in game be displaying row 1102 for row 1000. When the index array pointers of the struct become corrupted, it reads from
the wrong row location in the data table. Then I am forced to have to put in wonky values just to get it to read the data from the correct place.

What’s wrong with it now, is that When starting off the dialog, it is supposed to read in Rows 16-25 for the npc conversation but what its doing is reading in row 16, then jumps back to row 7 and displays someone else’s dialog row then reads row 17, 18, 19 of the npc its assigned to read then the data table suddenly resets itself jumping back to row 0 leaving a blank widget, then it displays the text rows 20,22,23 again then jumping back to row 7 its jumping back and forth to the wrong row locations So the data table struct array data pointers may be corrupted or some is missing in the logic in the code… Unreal Engine has a tendency to corrupt itself. Especially data tables with Structs.

I have been trying to resolve this problem now for two years. But everybody in the community has told me to just try to fix it myself, and I don’t have the knowledge to know how to fix this kind of bug. And that’s why I had the issue for such a very long time.