Migrate from 4.12 to 4.13 or 4.14 and crash on any blueprint opening

I’ve got a mainly blueprint project with a handful of c++ bits, and some plugins.

Whatever I do I just can’t get the project to migrate to 4.13 or 4.12. I’ve painstakingly removed requirements for my c++ classes (simply a URL decoder and one that creates an array of object references based on the content folder structure). And also made a version where i’ve removed use of plugins i’ve used (Blui, SQLITE, Victory and OSC).

Whatever I do I can’t load any blueprint without a crash or even right click.

I did start to think it was a sub-class I made of TextureRenderCanvas2D - I can open most structs, but one of them contained a variable of this type and caused an immediate crash. I thought I was on to something so I re-parented the class to an actor component and fixed up all of the mess it made, but - same problem again - crash on load but this time I can load that struct. (I’m now pretty sure the render canvas is a red herring).

In terms of the plugins - i’ve got another project which uses the same ones and there are no problems with them in 4.14, so I don’t think it’s that.

Are there any tools which can track down the issue - i’m sure it’s just one little reference somewhere which is causing the problem.

Here’s my crash log data

Thanks massively for any help here.

Ok, after about 3 days of blueprint destruction I finally traced the problem to a collapsed bit of blueprint, which only contained a bit of transform lerping and juggling - all pure calls, and only float variables used. I fixed the problem by remaking it node for node - so no differences, just some kind of corruption which brought my whole project to it’s knees!

Although I can now load my project in 4.14, I still feel that there should be a more elegant solution to tracking these kind of blueprint problems. I know everything is interconnected by references, but the idea that loading a struct for editing can crash a project because of a variable which isn’t even referenced in that blueprint makes it pretty hard to track things down.

I feel sure that Epic has some kind of solution to this sort of issue - they must always break projects by depricating functions etc.

Cheers!