My previous can't offer me contract due to issue. How to fix it?

[#1]

Hello Upwork team.

My previous client can't send me a new offer due to an unknown error. He says it keeps saying error and not letting him submit offer. How to fix it?

Here is a screenshot attached to this thread.

[#2]

Hi Larisa, 

Could you please ask your client to clear their browser's cookies or use a different browser to see if the issue persists? If it does, please ask them to contact Customer Support directly or post here in the Community so that we can assist them further.