See Reply #11. (Also works for Avast Free users.)
I saw that reply and actually started to submit the form, but how would “false positive” apply to this specific situation? There is NO virus warning produced (no “warning” at all) as it would be with suspected “infected” files.
And the program does show as “running” in the Processes tab of Windows Task Manager, but fails to load on the screen. So which file would likely be the one affected by Avast then? The program’s .exe file or one of the UI.dll files?
Try setting the behavior shield to ask.
Tried all possible settings for ALL shields, even turned ALL shields OFF and it made NO difference!
The only way I was able to get PaintShop Pro to open again was, by uninstalling the 17.2.2288 version and reverting back to an old version…which, as I just now noticed, “screwed” me too, because I forgot to turn off automatic updates for the Program, so it automatically (without notifying me) updated once again to version 17.2.2288…meaning once I shut the computer down tonight and restart it tomorrow, I will most likely find PaintShop Pro to be blocked AGAIN…unless Avast has suddenly fixed the problem which would amount to nothing short of a miracle!
I’ll let you know how it turns out, but don’t hold your breath! :-\
What version of PSP ??? Is it a legally registered program ???
I have the same problem. Updated free Avast about a week ago and since then Paint Shop Pro 9 will not launch in Windows XP Pro although it shows up in task manager. Also, the computer then hangs and will not shut down, I have to power off at the switch. I have tried the suggestion of putting Paint Shop Pro in the Settings> components> behaviour shield> customize but this makes no difference. Is Avast likely to fix this problem anytime soon?
disable
settings / troubleshooting / avast self defense module
(Unfortunately the exclusions do not work on self defense module and disable shields does not work either)
Disabling avast self defense module works, but is it safe to disable it? Avast please fix it.
Is that a problem before?
Normally an anti virus launches before the operating system, examines the memory and examines itself
Then it examines everything that moves, and a virus can only come from outside, and it will be examined and, unless excluded, quarantined before saying ouf: AVAST will not even ask you your opinion in silent mode
Personally, I think that if AVAST can do this, we do not need more
What is this module that does not take into account exclusions?
And here that does not even quarantine but blocks programs at launch?
I take the “risk” 
I have the same problem on my computer, but it allows me to use Photoshop,
But i don’t have free Advast i paid for mine and it upgraded a few days ago, so computer is just pile of crap right now
kjmartland: The problem is for Paint Shop Pro, not for Photoshop
Otherwise, it would mean that … ahahah avast = malware If you do not pay ?
Presuming you mean Avast 17.1.
Have similar problem but with PaintShopPro Photo X2 stopped working after free Avast upgrade. It’s there in Taskmgr.exe but no GUI.
Disabling all shields didn’t help. Works in Safe Mode and if I uninstall Avast.
Only thing that works is to go to Settings/Troubleshooting and unchecking “Enable Avast self-defense module”.
Not sure if it thinks there’s malware in the program but it doesn’t report it when I do a scan.
Thank you for posting this, for complicated reasons I had to do a rebuild of a legacy XP Pro machine with Paintshop Pro X that simply would NOT launch. Disabling Avast (17.2.2288) self-defence mode FINALLY let it launch. I wasted 6 hours on it trying everything and I would quite like my life back. >:(
That would indicate that something in PSP is accessing something within Avast. The self-defense module protects Avast from tampering. Primarily designed to prevent Malware from turning off the protection.
Disabling avast or even running windows in Safe mode does not help too.Guess what... avast doesn't run in safe mode. If you can't use PsP in safe mode, the problem is not avast but something else.
You can guess as many times as you want, it’s Avast self-defense module which do not let Paint Shop Pro to run. After disabling it, the program runs normally.
I had “freeze” for some time on a XP machine (reboot mandatory), I searched for a long time hardware, HDD, Memory … and also conflicting programs … it was random but regular: Between a few hours and a maximum of 2 days! and “couic” => freeze
Since deactivating the self-defense module, never again!
Grrr AvAST, AVASTT !!! :-*
This is certainly strange, bordering on weird.
Unless the function of the self-defence module has changed (and I haven’t seen anything in black and white), it should only prevent another process from accessing/modifying avast features/function/locations/settings.
Thanks for the link Bob.