I just bought a new 2020 model MacBook Air. I'm running Catalina 10.15.16 and I downloaded HL from the website and I get an error saying

"Hero Lab" can't be opened because Apple cannot check it for malicious software.
This software needs to be updated. Contact the developer for more information.

I hope this is the right place to be posting this.

Well, you answer help me to solve my problem

To bypass that type of issue, Phil, you will simply need to click "Show in Finder" when that error appears or otherwise locate the Hero Lab Classic software on your computer with Finder, Right-Click, and then use the context menu to select the alternative Open Option there. Once you do this you'll be shown a similar error window but this time you will be afforded the option to open the software anyhow.

Once you do this a single time your system should remember that you've done so an effectively whitelist the software, at least until the next OS update on that machine.

I'm still having sluggishness issues, like 4-5 seconds to switch tabs and scrolling down a long list of items can crash it or take about 35sec to finish scrolling.

2017 MacBook Pro with 3.1ghz I7 16gb ram on Mojave 10.14.6

The only other thing open is a browser not doing anything. Even happens when no other software is open.

I have tried reinstalling it to no avail.

I've tried to start using HLC again after a long break and a Pathfinder 2e stint. I am also having CONSTANT and unusable quantity of crashes as well as the extremely annoying "permissions" popups.

Something I have noticed, every time you go to security and toggle off Full Disk Access and immediately toggle it back on, you do not get any permission popups for the entire session. However, as soon as you close and then reopen the program, they come storming back.

I sent in a tech support request with crash logs and what I remembered what I was doing... but after just one hour of HLC and 4 crashes, it is completely unusable in its current state :/

I'm also getting unacceptable lag with my Hero Lab on my Mac.

If Hero Labs Classic is not being developed anymore, I'd want to know so I can begin looking for an alternative.

I don't mind shelling upgrade pricing for a working 64-bit version of Hero Labs (not barely working, but actually working), after all developers still need to make a living. But I'm not going to be investing any more money in this system (eg. in buying new books) if Hero Labs for Mac continue to lag like this.

I'm also having serious lag issues that is making it a pain to use (Shadowrun 5e)

IIRC, there was a bug in which fields weren't being updated when a dependent value changed. The workaround was for LW to turn on automatic recalculation of everything when any value changed. Since there's no one working on HLC at the moment, the bug is not likely to be fixed and the workaround is probably permanent.

I experienced the bug where things got incredibly slow and I have found a workaround.

If you go to /Applications and right-click on Hero Lab, you'll have an option to "Get Info", click on that, you'll then have an checkbox labelled "Open in Low Resolution Mode", check that.

The application won't look as sharp, but you won't be stuck waiting for many seconds each time you click or scroll.

Huh, that seems to work for me, and it's better than just being super slow, albeit a pain.

Does anyone know if Hero Lab works on Big Sur? With the lack of attention paid to Hero Lab on Mac, I'm a little concerned that it might not work on new computers/the new OS.