I know what you experienced. I accidentally uploaded the version in which you start with a one-shot weapon. Pressing reload should have fixed the issue, but the current version starts you with the correct starting weapon. Thanks for notifying me!
It still not working. Steps to reproduce:
1. Run game
2. Click "Play" (with mouse LMB)
3. Press "2" to select weapon
4. RMB to AIM (do not release)
5. LMB to shoot -- nothing happens
Here is a video (i'm clicking all the way) https://1drv.ms/v/s!Ao0qx4Sp-qCcqKRjeCKW-leIzcTMZA?e=dUmfWP
Thank you so much! I figured out what the problem was. Weapon selection can also be done by clicking the icons or hovering over them and letting go of Q. I pretty much always used this method and forgot to take the keyboard number selection out of developer mode, which causes all sorts of issues. It should work now, hope you can finally start rootin', tootin' and most importantly shootin'!