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Consumer Products => Avast Free Antivirus / Premium Security (legacy Pro Antivirus, Internet Security, Premier) => Topic started by: Cluster-Lizard2014 on July 03, 2019, 02:10:49 PM
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Is there a finite limit to the number of exclusions you can add to the AVAST global exclusions list?
I ask because I recently added about half a dozen new exclusion paths as I'd backed up a large number of files/folders, some of which were on the existing exclusions lists, to another HDD. So I needed to put in the new paths.
Once I'd done that I decided to do a full system scan just in case I'd missed anything and found AVAST reported at least a couple of dozen problems soon realised they were all files/folders on the global exclusions list. So I went to Settings > Global Exclusions and was surprised to find the list was completely empty.
After a bit of research I found out where the actual AVAST "exclusions" settings file is located and when I looked at it (opens with Notepad etc) all the existing exclusions and the ones I'd just added were still all there. I rebooted the PC and checked again; the exclusions list remained but AVAST itself obviously was not using it.
It was a big pain but I copied each of the paths shown in that list, which you have to do one by one, and re-entered them as paths in Global Exclusions. They all added OK until I came to the last one. I copied it directly as it was from the "exclusions" file as I had done with all the others and the moment I clicked "OK" the Global Exclusions list cleared completely.
Thoughts: either the last entry path was corrupt in some way OR there is limit to the number of exclusions you're allowed on the list.
The last entry path shown in "exclusions" was unusual in that the path was enclosed in quotation marks ie. "L:\.....folder location.....\file name". Nothing else is written like that in the list.
You see quotation marks being used when entering a path in the Global Exclusions list itself but when you click Add for the next one or OK the path shown, in that case, would be changed to L:\........folder location\.........file name or with an added \* if it was a folder rather than an individual file you were adding.
I've since added a limited number of paths to Global Exclusions and the old "exclusions" settings file list has gone replaced with a new one. This suggests to me that nothing in AVAST is broken, it has simply replaced the old "exclusions" file in the normal way.
So was this "exclusions" file corruption or an unreported exclusion list limit reached?
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Well, let me put it this way - the exclusions were never meant to contain huge lists. Having a lot of exclusions suggests something strange/bad is happening on the machine (say there's a lot of false positives - but that should be solved by fixing the false positives on our side, not by excluding everything), plus it can even slow things down (because for every scanned or accessed file, the whole list needs to be checked... again and again).
Yes, there may be some limit, but it's hard to say what it is (some features may not be affected, some might - by features I mean e.g. on-access vs. on-demand scanning). But the limit won't be the number of exclusions, but rather the overall length of all the added text. My guess would be a few kilobytes of text.
So, I wouldn't be surprised if the list got truncated at some point (either "visibly", or the exclusions at the end wouldn't work). However, it definitely shouldn't clear the whole list as you describe. I'm not sure if I understand correctly what's actually happened... so that "cleanup" of the exclusion list happened just one time and since then you added all the exclusions and it works now, or are you saying that whenever you add a specific(?) path enclosed in quotes, the list gets cleared?
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Apologies I used the word parenthesis in the first post (since corrected) - I meant quotation marks.
I have had this problem happen once before a long, long time ago and I was suspicious it was a perhaps a file limit thing. But I'd forgotten about it but once it went missing when I made the mistake of resetting AVAST. That was a known problem back then.
There's nothing strange with the amount of stuff I've added either really - maybe a couple of dozen paths but that also includes whole folder exclusions which typically contained several copies of different files AVAST finds suspicious.
The reason I have a list that long is just that I often keep multiple backup files of certain software tools I use in relation to my video gaming interests. These are tools that are almost impossible to find now so backups are essential. I also keep old copies of previous versions which may or may not be useful. I have a lot of stuff like that which regularly gets shifted to other storage drives some permanently attached. some not.
The problem is that AVAST treats their obscurity as suspicious as well as what they do. Things like font, image and video niche format converters it often flags up. It does not like highly compressed folders flagging them as zip bombs and hates anything that creates shadow C copies even though the tool set package is not designed to work on a PC.
There are file paths it does not like on dual boot or VM OS too where it will flag a problem simply because a path has not been found. It took me some time to understand that but it seems to be because unless the second OS is is actually booted that path does not exist. How are you supposed to submit a file from a path that does not exist for analysis?
It is simply easier to add it or its container folder to Global Exclusions and once done it is no bother any more..................until the exclusions list corrupts or hits some unrecorded limit which results in the same thing.
The only concerning thing is that the "exclusions" .INI was still there (C:\ProgamData\AVAST Software\exclusions) showing the previous list of exclusions but it was being ignored. When I copied in all the paths to Global Exclusions from that list I have no idea if it was working or not because, as said, copying in that last entry provoked the list to clear again.
Once I added and saved a new shorter set of exclusions file paths which did not included that last one, I assume, provoked AVAST to delete the old .INI and create a new one which is definitely being used as I've tested it.
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(because for every scanned or accessed file, the whole list needs to be checked... again and again)
That sounds very, very inefficient.
You can simply check the list once when starting to access a directory and sort out all entries not applying to any element in this folder.
Per file checking should only be necessary when ther are wildcards matching all files with the same name or same extension, whats very rarely the case.