Avast has a RED exclamation mark on the tray icon and this warning in the interface… what would it be? let’s see…
https://www.dropbox.com/s/ajeflljzbalfa57/avast-scam-1.png
oh oh, ominous “undefined” issues… let’s try to resolve them…
https://www.dropbox.com/s/knwcbprw49zd3ij/avast-scam-2.png
eww… it’s a marketing push for Cleanup Premium. wtf?
Where did you download Avast…!?
Never saw anything like “Almost Quick Scan”, it should say “Smart Scan”.
the “Almost quick scan” is a custom scan i created manually - look at the breadcrumbs path on top, you’ll see it’s in the “Other scans” category.
It’s actually a quick scan but tweaked to scan a few more areas, so i named it “Almost…”
and avast was installed from https://files.avast.com/iavs9x/avast_pro_antivirus_setup_offline.exe
Got it. 
Just get rid of Cleanup if you don’t want/need it.
→ https://www.avast.com/faq.php?article=AVKB96#artTitle (Add/Remove components)
Don’t install everything when installing avast free, do a custom install and only install components that you want or need. As far as I’m concerned, browser cleanup and avast cleanup don’t fall into that category, there are others. If you have these components installed if you run a Smart Scan then these additional components are very likely to generate these marketing ads.
Rarely do I see these ads/marketing, partly because I rarely run on-demand scans, a depreciated value in a resident on-access antivirus.
Why not use CCleaner from Piriform, recently purchased by Avast Software, use the free version it does most of the things that Avast
EDIT: From your Reply #2 you say that you used the files.avast.com/iavs9x/avast_pro_antivirus_setup_offline.exe, yet your images show the avast free version has been installed and not Avast Pro, which you could disabled ads.
oh, i actually downloaded the free but linked pro up there.
i usually copy the link in the forum from https://forum.avast.com/index.php?topic=205786.0
and change http to https for the files server link. I think i copied the pro link for that reply blush
and P.S… that’s the thing… not even the free Cleanup is installed. the attached pic shows how i have it installed and even then the warning/ad for Cleanup Premium still appears.
Doesn’t matter, Cleanup is a standalone product anyway.
Well, that’s strange.
Best you perform a clean, custom! reinstall…!!
sigh if Avast is going to keep that ad there on purpose then at least please disable the silly red exclamation mark on the tray icon. 
No exclamation mark but a “1”, check your notification center.
That’s not an ! but a 1 and indicates One notification.
Open the User Interface, select the Notification and clear it.
http://screencast-o-matic.com/screenshots/u/Lh/1503773694094-10350.png
headscratch indeed there’s a notification… that my custom scan has completed successfully and no issues were found.
Weird choice of a colour then, a red tray icon marker for a green condition status.
And that number font is barely readable even on a full HD screen
Is nobody doing UI usability testing for such small-size elements that are designed to be always on screen?
The devs are already working on it…
Well I have just ran a Quick Scan, whilst I didn’t get an exclamation point (nor any number) over the tray icon on completion of the scan even. I did get the little 1/4 panel at the bottom of the UI for the improve performance click bait. The 1/4 panel has essentially been an ad/promo click bait window.
My system I used (my win10 Home 64bit laptop) is anything but lacking performance.
Acer Aspire F15 F5-573, Intel Core i5-7200U @2.50GHz to 3.1GHz, 8GB DDR4 RAM, GeForce GTX 950M 4GB DDR5, 256GB SSD primary drive 1TB HDD secondary drive.
This looks like Avast is using any opportunity to throw up the ad, click bait and running a scan seems to be the starter for ten. Even if you haven’t got the free cleanup component installed, so how would it determine you have a performance issue.
I followed it through to the point where it offered 30 free trial or 1year at £x per month. To be brutally honest the monthly rate is extortionate for what cleanup is purported to do. More so when you can get CCleaner (now Piriform is part of Avast Software) to do pretty much the same for free, unless Avast have plans for that.
Performance issues doesn’t necessarily mean a weakness in the computer’s hardware.
In this case it’s a reference to how things are configured and and things that may be installed that can slow the system down, etc.
I think by now you know me, I don’t have lots of cr4p installed on my systems. Even on this win10 laptop it has less on it has a total of 33.6GB used on my C: drive 256GB SSD primary drive and 57GB used on my 1TB HDD secondary HDD drive
I also know that one shortcut not working or one registry entry left after an incomplete removal,
is enough to trigger the warning. As you said, ecommerce would like you to purchase the paid version.