So, okay, at first I wanted to mention that I did try updating Cookie.txt, with new gog-al value (but forgot during the message editing). Updating cookie file didn't change the situation at the time.

Just now I checked out gogcli instructions on GitHub again, and noticed that
sessions_gog_com=<value taken from gog.com>
gog-al=<value taken from gog.com>

are both needed (missed that while checking the same issue with gogcli alone, I just reused GUI cookie file with only gog-al, my bad, might have realized what to do with GUI).

I added "sessions_gog_com=" with respective value from browser to Cookie.txt in GUI folder, with new gog-al value and now everything works.

I didn't change Cookie.txt file ever since that "Download All" odyssey, back in April.

Do you have/need "sessions_gog_com=" value in your Cookie.txt?

No, I realized early on, that it didn't appear to be needed ... at least for me.

Good news that you have everything working again.

I just want to say thank you for that suggestion, it was the issue that was causing me grief, and thanks to finding your post, is now solved!

I was having the same issue as guardianali after copying over my GOGCli folder to a new PC, and was losing my mind. Everything worked great except my downloads would always fail. Made a new cookie.txt and my downloads would fail. Redownloaded GOGCli and the GUI and got it all set up; the download would fail. Finally came to the forums looking to see if there was any other users having this problem or any solution I could find, and lo and behold: the folder I was trying to download to was set to Read-Only for GOG knows whatever reason. The one thing I never checked or even thought about. After unticking the “Read-Only” box, downloads are working perfectly again. Ugh!

Good to know you got it solved.

I really must get around to dealing with my issues with GitHub, and upload some updates, because updates have continued on a regular basis, and my GUI can do so much more now, including a bunch of fixes. I am up to v6.8 now.

A heads up, for those that might be interested in such - an MD5 database.

I'm currently working on a complimentary program, that some folk might like, especially those that don't use Galaxy or a 3rd party downloader, and just use the browser links to download GOG game files.

At this point I am calling it MD5gog Bank.

Basically it is a database program for MD5 and Bytes values for GOG game files.
It's also a program based on folk here sharing and contributing, and will really only work well enough if a good number of folk here do that.

The program features drag & drop onto a drop zone.
What you can drag & drop is a game file, or a Manifest.txt file from my GOGcli GUI program, or the gog-manifest.dat file used by gogrepo.py users.

The manifest files will be scanned and data from them entered into the database. The data is MD5 values, Bytes values as well as Game ID and Title, along with related file names of course. Existing entries are skipped. It may also include a drive serial and PC user name, for assistance with verifying created entries, but I am still pondering over that.

You can also validate the MD5 or Bytes value of a game file, if it is present in the database, or create those values, which can then be later verified by other users (hence the probable need to differentiate between users).

The program also supports the use of 7-Zip to test game extras zip files.

I'm going to all this effort, because yet again GOG have changed something in their API/SDK, and bad metadata is being returned for some game files ... again. Having a slow single thread connection to GOG, can mean a long time taken to get MD5 values for some game files.

At the moment the program is just using a simple basic INI file database, but if enough interest is shown, I will look into reviving my SQL know how and use an SQL database instead, which should give a good increase with importing speed when the database grows large.

The idea, is you share your database file (and program) with others, who add to it and or test with it, and then share the database file back etc.

Validating is currently working, and most of the importing code is done, and once that is complete I will work on the create and add side of things.

I will likely end up giving the program its own thread, but if you are interested in this project, and want to give me written encouragement, you can do so here for now. Due to the nature of this program, I may not bother to set up things to share etc if the interest is clearly not there. Viability relies on a joint community effort.

See the screenshot.

DISCLAIMER
This program is not being developed by or contributed to or supported by GOG.com, or even endorsed by them.

Alright, I have completed the IMPORT code, with the exception of a manifest file created by gogclic.exe, but not built by my GUI, as I would need to see one that has more than one game in it, just to see if there are any differences that might impact.

If anyone wants to play with my program as it is, no CREATE or ADD yet, then you can grab it from MEGA.

Download from MEGA

Please give me some feedback if you do try it.
And of course, share your 'Database.ini' file here if you have imported entries to it.

The zip file (946 Kb) also includes my 'Database.ini' file (1.63 Mb), which currently contains values for 11,648 GOG game files.

IMPORTANT - If your AV program complains about my program, then please use VirusTotal to allay any fears. The compiled files of the programming language I use (AutoIt) often get false detections. You would then need to add an exception to your AV program for my program.

NOTE - Alas, only Windows is supported, though you could try Wine etc. Usually the programming language I use, doesn't work well with Wine or it might be a matter of how I do my coding. If you have success with Wine etc, I'd certainly like to hear about it.

ADVISE - A side benefit no doubt, for all Offline Installer downloaders, is that the database could include MD5 and Bytes values for a wide range of file versions for a game, perhaps all ... dependent on the contributors of course.

--------------------------------------------------------------------------------

My current thinking in regard to ADD and CREATE, is to require InnoExtract testing for installer files (EXE and BIN) and 7-Zip for game extras files, plus the Linux and Mac installers. A side benefit of using InnoExtract, before going onto creating an MD5 value on success, is that the top of the output file contains the Game Title and ID.

The usual process for InnoExtract testing, is to use the EXE file to test that and all related BIN files. Testing with InnoExtract can be a very lengthy process with large installer files ... essentially it is checking every file within the EXE or BIN archive, against the included manifest list that has MD5 values for every file, so with a lot of files, especially big ones, it can take a long time.

How powerful your PC is, will certainly be a factor when it comes to speed of InnoExtract testing and MD5 testing and creation, plus importing to the database.

It is with some reservations, that I finally share the latest update of my GUI program for gogcli.exe.

GOGcli GUI v9-2 is no longer the simpler beast it used to be.

I have held back from sharing more recent updates, because I don't really have the time to create more tutorials or give much instruction.

The 3rd party free program, curl.exe is required for some data retrieval and can optionally be used for downloading. You can even use it with aria2 or Free Download Manager 5 to gain a significant download speed benefit. Be advised though, that FDM5 is tricky to setup.

I am no longer providing via GitHub. You get a Rebrandly link (for download counter) for a MEGA download link.

I don't recommend using my GUI, which also requires latest gogcli.exe (24.1), unless you are fairly savvy with software.

DOWNLOAD

GOGcli GUI v9-2 has had a lot of bugfixes, improvements and new features since I last uploaded.

For those of you willing to try it, Enjoy!

Discovered a bug in GOGcli GUI today, that crashed the program due to a missing ampersand in error dialog code, when your cookie text file no longer works ... mine needed updating, hence the discovery.

I've updated and uploaded the fixed version, but not given it a new version number, so hopefully the download link will still work, as I just overwrote the last version at MEGA. Please let me know if that is not the case.

In any case, renewing your cookie text files, would prevent the dialog error crash, if it had occurred for you.