Not accpeting large blastn output files

I have a blastn output file
When i upload a subset of my data it gives me a tree and an expected result, where as when i upload the entire (5GB) blastn result file , Megan gives the following error.

Too many errors
Error: Execute failed: Too many errors
Induced tree has 2,031,708 of 2,031,708 nodes
Executing: close what=current;
Invalid argument

I have MEGAN6 LR version and i am using it on Linux 16.04 (ubuntu)

Please guide me through it.

What other messages appear in the message window? I don’t think that this problem is due to size, 5 Gb isn’t particularly big.