Do you still have a list of tools on the right hand side, or has the space gone away?
I do but it only has fill and sign, comment and send for signature. Under more tools there is no conversion option
Is this the English language version?
Did you install it, or did your company do it for you?
What is the version shown under Help > About Acrobat Reader, something like 2016.123.94403?
Yes English version. I installed it on my work pc as I bought a person subscription. version 18.011.20038.5321
After checking all the suggestions provided by Test Screen Name, I happen to check your subscription status using the email id you are logged-in on Adobe forums I see it was suspended for some time and then it was later cancelled.
If you want to get this resolved you may try to subscribe to the service again. Feel free to update the discussion if you have further questions.
Did your work PC have an Acrobat Reader before, from your company? A company can turn this stuff off. Does your company maybe have a policy that your files can't be sent out of the company for any reason?