[4.7.6] Must recompile blueprint to make class visible again

Hi there,

In my project a got a simple structure of ‘lights’ blueprints:


Both _halogen and BP_xenon derive from the base class BP_light.

After closing my project and reloading it, all references to BP_light_xenon get lost, it is also not listed in the blueprint editor for each variable slot with type BP_light:


(BP_light_halogen is listed but BP_light_xenon is missing now).

I have to manually recompile the parent blueprint and the childs each time to regain access to this derived blueprint class which is not only super-annoying (because I have to do this with my function libs as well after re-opening the project) but it destroys all the references to it each time.

I know this might be hard to reproduce but it’s really happening at least once a day in my project.

Hi ,

Has the BP_light_xenon class been moved in the content browser recently? Additionally, does this occur in a clean, blank project with no additional content or is it limited to this specific project?

Hi ,

yes, the classes have been moved. Seems to be a problem with broken redirectors or something. Is there an option to move files without creating these invisible redirectors? Got plenty of trouble with them for various reasons…

The only other option would be to remove references before moving. However, if you right click the “Contents” folder in your content browser and press “Fix up redirectors”, it should go through and fix the broken references throughout the entirety of the contents subfolders. Let me know if this fixes your error.

Thank you , I will try this and report back.
But I don’t get, why recompiling fixes the problem temporarily…?

Hi ,

Did the fix work for you or are you still receiving the same error?

Hi ,

sorry for not reporting back as promised. I did “Fix up redirectors” and restarted the engine. Since then, everything worked as expected. It seems like there really was some broken redirector or something. Thank you.

Hi ,

Not a problem at all. I’m happy to hear this is working for you now. I will go ahead and mark this thread as answered for tracking purposes.