Drupal 6.x

Hello! I'm looking for some help with Drupal 6. I understand 6 is old and I guess unsupported now, but can't upgrade at this time.
We had a company design our website a few years ago and I can't seem to get help now.

I have used weeks to figure out why I get this error but haven't found a solution yet and hope some one can help, please?

When editor update a node get a lot of these errors for each node that get updates:

Message Duplicate entry '14-1179' for key 'PRIMARY' query: INSERT INTO term_node (nid, vid, tid) VALUES (383, 1179, 14) in /home/www/MY SITE/modules/taxonomy/taxonomy.module on line 724.

Don't see this error if I as admin update a node.

Hi,

I am from India and I want to migrate to Canada for the Job.Can anyone please tell me what salary a Drupal developer can get with 8 years and 6 months experience in a full time job?

With the announcement that support for D6 is ending soon, I have to seriously plan for a migration now. I've avoided upgrading to D7 but will not go straight to D8. I'd like to get some general guidance before I go too far.

(1) I run a custom theme on my D6 site. Will this migrate to D8 or will I need to redesign it for D8?

(2) I make some use of Chaos tool suite, Drupal Wiki, Forum and Advanced Forum modules. Are these all migratible to D8?

i have migrate mysite drupal 6 to drupal 7 and add a file field in one content type, file field is not working it may error occured not create field and also content type, now how do i fix this error?