zsh-autosuggestions
                                
                                
                                
                                    zsh-autosuggestions copied to clipboard
                            
                            
                            
                        /Users/ice/.oh-my-zsh/custom/plugins/zsh-autosuggestions/zsh-autosuggestions.plugin.zsh:source:1: no such file or directory: /Users/ice/.oh-my-zsh/custom/plugins/zsh-autosuggestions/zsh-autosuggestions.zsh^M
/Users/ice/.oh-my-zsh/custom/plugins/zsh-autosuggestions/zsh-autosuggestions.plugin.zsh:source:1: no such file or directory: /Users/ice/.oh-my-zsh/custom/plugins/zsh-autosuggestions/zsh-autosuggestions.zsh^M

macOS: 10.13.6 zsh --verison zsh 5.8 (x86_64-apple-darwin17.7.0)
I installed it git clone git://github.com/zsh-users/zsh-autosuggestions $ZSH_CUSTOM/plugins/zsh-autosuggestions
I have the same problem. WSL 2.0
lsb_release -a                                                                                                                                                        No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.4 LTS
Release:        18.04
Codename:       bionic
zsh version zsh 5.4.2 (x86_64-ubuntu-linux-gnu)

I had this same issue in WSL2, it was due to CLRF line endings on the files. Once I switched them to LF it worked fine.