Whenever I try to import the final character in BG1 into BG2, I get a game freeze. It occurs with both the the character save file and the final save game from BG1. I've looked through all the old message board topics, none of the fixes work (delete bio files; run as admin/XP compatbility blah blah). Is there anything that people are getting to work? (Windows 10).

Creating a new character duplicating the old one just doesn't feel the same. Besides, I had used all the stat-increasing manuals from BG1 on him.

TIA

This works fine for me using a save game created in Baldur's Gate: Enhanced Edition v2.5.17.0 to import a character into Baldur's Gate II: Enhanced Edition v2.5.16.6. These are the most recent 32-bit builds of the game. (The 64-bit builds don't work here, so Beamdog's "improved compatibility by moving to 64-bit" means that I can't actually use the "improved compatibility" versions at all.)

To your problem, what versions are you using? You didn't say, and that may make a big difference. I've never seen the problem you described, and never had to apply any workarounds. If you obtain a saved game from someone else, can you import that character into BG2? That would tell us whether the problem is a bad game generated by your BG1 or a bad import when your BG2 tries to process a good game. Similarly, do you have a friend with BG2 that you could have try to import your BG1 character on that person's computer? This would be another test of whether your savegames are broken or your BG2 is misbehaving.

If you start a new character in BG1, and immediately export it (don't even bother finishing the prologue), can that character be imported into BG2 or does it also freeze BG2? How severe is the game freeze? Are you able to back out of the import using the game's menus, or are you forced to use Task Manager to kill the broken BG2?

Versions were recently downloaded from GOG.

BG1: 2.6.6.0
BG2: 2.5.26498.

As described in the original post, problem is occurring with characters and files imported from the final save of BG1;
my own game not something copied from somewhere else.

Yes, I understood that. I suggested you try acquiring a save from somewhere else, preferably from someone who has successfully imported a character into BG2, to determine whether the problem is that your BG1 writes characters that cannot be imported by anyone's BG2 or that your BG2 fails to import valid characters that other people can successfully import.

You're not supposed to import from 2.6 to 2.5 but only : from 2.5 to 2.5 or from 2.6 to 2.6

Do you have a source for this? I knew that trying to save a campaign in 2.5 and then load it in 2.6 was explicitly discouraged, but I wasn't aware that even importing a 2.5-era character into a 2.6 engine was unsupported.

Ah, just figured it out. I am trying to import into BG2 (original) from BG1 EE.
They don't seem compatible. Going from original and EE to EE works fine.

My memory, but I don't think it's as reliable as it seems :)
TBH, I have never tried myself.