Metadata error importing unityPackage

Hellow there,

I recently imported an unityPackage into my project, and my project crashed and now, whenever i restart it, it pops up an error message and my unity shuts:

" Type == kMetaAssetType & pathName.find("library/metadata*") != 0 "

I've tried to manually delete the installed asset folder but the metadata error continues,

Anyone please could help me fix this ? I don't have a backup from this project.

Thank You very much