Can't enter my host world with a client mod

The issue is more about the mods themselves rather than the game (Since you said you can play with them turned off.). Try testing them one by one and see which one is causing the crash (Unless you're using just one). But Klei doesn't fix mod issues, that's more along the lines of the mod creators job; to fix bugs that the mod may cause.

@abdo9966 This crash is caused by the Too Many Items mod you are using. There should be a fixed version or up to date version on the workshop