DownLow

I found out why the option for "TrueCrypt Mode" was always activated for me: The file ending was still .tc from TrueCrypt even though it was a VeraCrypt file. When I change the name to be .hc, the option is not activated anymore.

Windows 10, version 1903, build 18632.535 VeraCrypt 1.24-Update2 (64-Bit)

I experience the same problem and found out it is the option "TrueCrypt Mode" in the mounting dialog which is always activated for me even though I deactivate it in the "Default Mount Parameters". When I uncheck this option I can mount my containers again. Maybe it works for you also. Until this is fixed, I will downgrade to a prior version.