I am faceing an error of 

Whoops, looks like something went wrong.

to create or to open the invoice. 

I request you to Solve me problem.

Hi Pranav,

How about you provide more details so that anyone willing to assist you may detect where the error is coming from.

Are you refering to self host or Akaunting.com platform?

If it is selfhost then which version is your installation?

Generally, this error occur when the general info is not fully completed, so make sure you first go to settings > general and fill all the tabs accordingly. Lastly make sure your billing currency matches that of the client that you are trying to invoice

Thanks Thebe Phele, worked on the web version as well for me.