Hi Alex,
I have a problem which is very similar to the one described here: #1277 posted by @cnk113.
However, in contrast with the original post, my problem is not solved when running this with the latest version of STAR (2.7.10a_alpha_220314).

I have 3 different 10X datasets (3' gene expression), with 417M, 538M and 619M reads respectively. When running the code without multimapping, everything goes fine. When activating the multimapping (--soloMultiMappers Uniform), I only get an output for the first sample (417M reads). For the other two, I get an error message like:

STAR version: 2.7.10a_alpha_220314 compiled: 2022-03-30T12:27:55+0200 ln1.leibniz:/data/antwerpen/205/vsc20587/software/STAR/source
Apr 29 11:45:32 ..... started STAR run
Apr 29 11:45:39 ..... loading genome
Apr 29 11:45:46 ..... started mapping
Apr 29 12:35:49 ..... finished mapping
Apr 29 12:35:50 ..... started Solo counting
malloc(): invalid size (unsorted)

However, when lowering the number of reads via the --readMapNumber option to 400M, I got an output for the sample with 417M and 619M reads, but nog for the 538M reads sample (same error message as above). When further lowering to 200M reads, I got a valid output for all three samples.

Any idea how to solve this issue?

The command I use is:
$star_bin
--readFilesCommand zcat
--readFilesIn $fastq_file_2 $fastq_file_1
--runThreadN $threads
--soloType CB_UMI_Simple
--soloCBwhitelist $bc_whitelist
--soloCBstart 1 --soloCBlen 16
--soloUMIstart 17 --soloUMIlen 12
--soloFeatures Gene
--genomeDir $genome_index_dir
--soloMultiMappers Uniform
--outFileNamePrefix $out_prefix
--alignIntronMax 1
--outSAMtype BAM Unsorted
--soloCellFilter EmptyDrops_CR 16000 0.99 10 45000 90000 500 0.01 20000 0.01 10000

Best,
Pieter