Projects with 2^31 samples or more (just over 13.5 hours at 44100 Hz) will not re-open correctly. Higher sample rates mean proportionally shorter times - so just over 6 hours at 96,000 Hz. We know the cause, and do intend to address this bug. Workaround: Before saving or closing the project, export to audio files of appropriate size, or cut and paste sections of audio containing less than 2^31 samples to new Audacity projects and save those.
Was that the complete log? The log would be filled with warnings about “orphan block files” if you had gone over the 2^31 samples limit. What does the audio look like - is it the correct length but completely silenced?
If that is the reason for the problem, the project should open in 2.0.6-alpha which has a fix for that issue. Download the build from the top of this list: gaclrecords.org.uk .
OK, I assume because you have not clicked “Continue with repairs in log”, you have not yet seen the “orphan block file” messages.
Your audio is longer than the limit of 2^31 samples so your only chance of opening the project without a lot of extra effort is to use the 2.0.6-alpha. It is not an installer program.
“Close project immediately” in 2.0.5 then File > Exit 2.0.5.
Right-click over the 2.0.6-alpha zip file and choose “Extract All…”. Click “Extract”. You will now have a folder that contains the extracted files. Open that folder and double-click on “audacity.exe”. This does not install 2.0.6, but you can run 2.0.6 without it affecting the installation of 2.0.5.
The next 2.0.6 release of Audacity should be out fairly soon. It has the same fix for 2 ^31 samples so you can install 2.0.6 over 2.0.5 when the 2.0.6 release installer comes out.