Very simple by using the following SQL-Query (this simply reconnects the ibd to the frm, this connection is only saved in ibdata1 in the parent directory):

ALTER TABLE tablename IMPORT TABLESPACE;

Even in 2025 with support by copilot and deepseek i wasted 10 hours finding a solution...

HeidiSQL was showing views, but no structure, but in csv-import all fields appeared, using sql-dump all structure appeared, even comments, but wrong varchar lengths (1), but setting generous worked fine, if too short, rest of line gets damaged. in that case, just make sure ibd is saved somewhere else, drop table, change structure, import table again, check again ...

HxD showed me the fieldsizes in maxbytes, so varchar(200) becomes 800, as i used standard mb4 coding, but i was too lazy to do that for all fields in all tables in all databases ...

Then i decided to give DBeaver a try, as consistently suggested by AI (MySQL Utilities completely outdated and Shell also not working), where I saw the correct lengths.

So only then i decided to just try to follow the last step only of AI advise:

1. backup (no need)
2. create identical named (no need) table in second instance (no need)
3. drop tablespace (only deletes ibd, no need, especially on the original)
4. import tablespace (the solution)