When a player connects to a FiveM server, the server attempts to download and synchronize these custom files. If the server relies on a resource that calls for adhesive.dll (or a script that mimics a DLL interface), and that file is missing, corrupted, or blocked, the client cannot complete the handshake. The result is a hard crash or a load-screen lock, accompanied by the infamous error message. In essence, the "adhesive" has failed; the pieces of the modded server cannot stick together.
This is the simplest and often most effective fix. adhesive.dll often needs elevated permissions to hook into Grand Theft Auto V. adhesive.dll fivem error