Note: This article has the reference to the issue with the fix available:
"It was impossible to add a DNS record of the “TXT” type longer than 255 characters. Now, this limitation is increased to 512 characters."
- Plesk Onyx 17.5.3 23 March 2017
Unable to add a DNS TXT record longer than 255 symbols.
This is internal Plesk issue with id #PPPM-4778 .
The issue is fixed in Plesk Onyx 17.5.3. The limitation is increased to 512 characters.
As workaround use the following custom fix:
Note this fix has been tested for CentOS 7.3 and CloudLinux 7 only.
1. Save the following files and change them with attached:
2. Create a backup of 'psa' database. How to backup/restore a Plesk database dump?
3. Enter psa database and execute the following queries:
alter table dns_recs modify column val varchar(512) not null;
alter table dns_recs modify column displayVal varchar(512) not null;
alter table dns_recs_t modify column val varchar(512) not null;
alter table dns_recs_t modify column displayVal varchar(512) not null;