[Error Message] Datacache Forumpermission problem

[kant88]

Dear all,

I'm using MyBB 1.6.10 and I have a big problem with Datacache table, forumpermission field.

Every time that I try to change permission of one of my forums, or rebuild forumpermission cache, I receive always the following error:

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
2006 - MySQL server has gone away
Query:
REPLACE INTO mybb_datacache SET title='forumpermissions',cache='a:89:{i:0;i:0;i:101;a:23:{i:1;a:18:{s:3:\"pid\";s:3:\"915\";s:3:\"fid\";s:3:\"101\";s:3:\"gid\";s:1:\"1\";s:7:\"canview\";s:1:\"0\";s:14:\"canviewthreads\";s:1:\"0\";s:21:\"canonlyviewownthreads\";s:1:\"0\";s:16:\"candlattachments\";s:1:\"0\";s:14:\"canpostthreads\";s:1:\"0\";s:13:\"canpostreplys\";s:1:\"0\";s:18:\"canpostattachments\";s:1:\"0\";s:14:\"canratethreads\";s:1:\"0\";s:12:\"caneditposts\";s:1:\"0\";s:14:\"candeleteposts\";s:1:\"0\";s:16:\"candeletethreads\";s:1:\"0\";s:18:\"caneditattachments\";s:1:\"1\";s:12:\"canpostpolls\";s:1:\"0\";s:12:\"canvotepolls\";s:1:\"0\";s:9:\"cansearch\";s:1:\"0\";}i:2;a:18:......

I tried also to load an old backup, to load datacache table from a new installation, to delete the content of forumpermission field, but I didn't fix the problem!

Could you please help me? The address of my board is http://www.amada-engineering.eu/forum_aee/

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Please let me know if you need access rights!

[frostschutz]

This user has been denied support.

Usually, "MySQL server has gone away" is a host problem.

However it may also be a problem with the size of the cache. If you happen to have hundreds or thousands of groups, and forums, and custom permissions, you may be hitting some limit or other. MyBB is not optimized to handle extensive/complicated permission structures.

So how large is this cache, or how many forums, groups, etc. do you have altogether?

[kant88]

I fixed the problem changing MySQL parameters!