Streamed search execute failed because: Error in 'lookup' command: Failed to re-open lookup file

[LearningGuy]

Hello,

I received the following error, the issue resolved itself after 4 hours.  The CSV file size is 54 MB. 
Streamed search execute failed because: Error in 'lookup' command: Failed to re-open lookup file:
'opt/splunk/var/run/searchpeers/[random number]/apps/[app-name]/lookups/test.csv'

I am aware that there already a post in regards this, but I have more questions
1)  What is the cause of this error?    
Is it because of the bug like mentioned in the old post below?  I am running 9.0.4, the bug should have been fixed
https://community.splunk.com/t5/Splunk-Enterprise/Message-quot-Streamed-search-execute-failed-becaus...

2) a) Is it because max_memtable_bytes in limits.conf  is 25MB?
https://docs.splunk.com/Documentation/Splunk/9.0.4/Admin/Limitsconf

b) How do I check limit.conf via GUI without admin role?

c)  What does "Lookup files with size above max_memtable_bytes will be indexed on disk" mean?
     Is it a good thing or bad?

d) If I see cs.index.alive file auto generated, does it mean it's an indexed on disk?
[random number]/apps/[app-name]/lookups/test.csv
[random number]/apps/[app-name]/lookups/test.csv_[random number].cs.index.alive

3)  If I am not allowed to change any setting (increase 25MB limit),   
     what is the solution for this issue?

I appreciate your help. Thank you