I tried v108.2, v108.1, and dev v108.3. All of them failed to unpack on "omni.ja".
However it seems I can unpack the files manually just fine with Total commander, or 7-zip.
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I just installed it to my Desktop directory here without issue. Please include more details that were requested like "system details (OS version, 32 vs 64-bit), install path, new vs upgrade, etc." Also include your Windows language and what antivirus you are using.
This specific error usually shows up when either using a very deep directory structure, having disk errors, or having an antivirus issue.
Lastly, please try testing a fresh install to your Desktop directory. You can delete it after it installs.
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