I fixed a bug in Tabulate last night, and released version 2.10.3. I’ve rather been neglecting this project for a while, so it’s been nice to come back to it. There are a few things that I might try to get done on it in the next few days or weeks (starting with more documentation).
The bug was to do with the change in WordPress’ default database character set and how that affected the reports ‘title’ column. Previously, a key length on this column of 200 was okay as it was under MySQL’s maximum of 767 (i.e. 767 bytes / 3 bytes for utf8 = max. 255 characters), but now the default is utf8mb4 each character can use up to 4 bytes instead of 3, and so the length must be reduced to 191 (i.e. 767 bytes / 4 bytes for utf8mb4 = max. 191 characters). WordPress core only does this for sites running on MySQL 5.5 and above, but it seemed easier just to reduce the key length for all Tabulate installations; it doesn’t seem likely to be an annoyance to anyone.